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Showing papers on "Peptide sequence published in 1979"


Journal ArticleDOI
29 Mar 1979-Nature
TL;DR: The nucleotide sequence of a 1,091-base pair cloned cDNA insert encoding bovine corticotropin-β-lipotropin precursor mRNA indicates that the precursor protein consists of repetitive units and includes a third melanotropin sequence in its cryptic portion.
Abstract: The nucleotide sequence of a 1,091-base pair cloned cDNA insert encoding bovine corticotropin-beta-lipotropin precursor mRNA is reported. The corresponding amino acid sequence indicates that the precursor protein consists of repetitive units and includes a third melanotropin sequence in its cryptic portion. Pairs of lysine and arginine residues separate the component peptides of the precursor.

1,689 citations


Journal ArticleDOI
01 Dec 1979-Nature
TL;DR: The nucleotide sequence of the 1,102 base pair region between the directly repeated IS1 sequences in the bacterial transposon Tn9 (encoding chloramphenicol resistance) is determined and the amino acid sequence of CAT predicted from theucleotide sequence is identical to that determined by Shaw and coworkers.
Abstract: The transposable genetic element Tn9 consists of two direct repeats of the insertion sequence IS1 flanking a region of 1,102 base pairs which determines chloramphenicol resistance. Transposition of Tn9 leads to the duplication of a 9-base pair sequence which preexists at the site of insertion. One copy of this sequence is found at each end of the inserted element. The chloramphenicol resistance determined by Tn9, and by various other R plasmids, is due to the synthesis of the enzyme chloramphenicol acetyl transferase (CAT). This enzyme catalyses the formation of acetylated derivatives of chloramphenicol which are inactive as inhibitors of protein synthesis. By using the chain termination technique of DNA sequencing, we have now determined the nucleotide sequence of the 1,102 base pair region between the directly repeated IS1 sequence in the bacterial transposon Tn9 (encoding chloramphenicol resistance). The amino acid sequence of CAT predicted from the nucleotide sequence is identical to that determined by Shaw and coworkers. An analysis of the sequence suggests that the internal 1,102 base pair region is not directly involved in transposition.

457 citations


Journal ArticleDOI
10 Aug 1979-Science
TL;DR: The data reported predict the previously unknown sequence of the signal peptide of human growth hormone and strengthens the hypothesis that these genes evolved by gene duplication from a common ancestral sequence.
Abstract: The nucleotide sequence of a DNA complementary to human growth hormone messenger RNA was cloned; it contains 29 nucleotides in its 5' untranslated region, the 651 nucleotides coding for the prehormone, and the entire 3' untranslated region (108 nucleotides). The data reported predict the previously unknown sequence of the signal peptide of human growth hormone and, by comparison with the previously determined sequences of rat growth hormone and human chorionic somatomammotropin, strengthens the hypothesis that these genes evolved by gene duplication from a common ancestral sequence. The human growth hormone gene sequences have been linked in phase to a fragment of the trp D gene of Escherichia coli in a plasmid vehicle, and a fusion protein is synthesized at high level (approximately 3 percent of bacterial protein) under the control of the regulatory region of the trp operon. This fusion protein (70 percent of whose amino acids are coded for by the human growth hormone gene) reacts specifically with antibodies to human growth hormone and is stable in E. coli.

410 citations


Journal ArticleDOI
TL;DR: Isoelectric points and charge distribution within the native protein, the apoprotein and the cyanogen bromide fragments, a buried pyrrolidonecarboxylyl amino terminus, heterogeneity at the carboxyl terminus are discussed, and a possible domain structure, likely from partial tryptic digestion is discussed.
Abstract: Horseradish peroxidase C dominates quantitatively among the isoperoxidases of horseradish root and has an isoelectric point close to 9. It consists of a hemin prosthetic group, 2 Ca2+ and 308 amino acid residues, including 4 disulfide bridges, in a single polypeptide chain that carries 8 neutral carbohydrate side-chains. The molecular weight of the polypeptide chain is 33890. Assuming an average carbohydrate composition of (GlcNAc)2, Man3, Fuc, Xyl for each carbohydrate chain, the molecular weight of native horseradish peroxidase C is close to 44 000. Cyanogen bromide fragments of reduced and carboxymethylated apo-peroxidase were purified by a combination of gel filtration and isoelectric focusing in urea, and cystine-containing tryptic fragments of apo-peroxidase were purified by gel filtration followed by disulfide cleavage and rechromatography at the initial conditions. The present paper discusses (a) isoelectric points and charge distribution within the native protein, the apoprotein and the cyanogen bromide fragments, (b) a buried pyrrolidonecarboxylyl amino terminus, (c) heterogeneity at the carboxyl terminus, and (d) a possible domain structure, likely from partial tryptic digestion.

380 citations


Journal ArticleDOI
TL;DR: The complete primary structure of the purple membrane protein bacteriorhodopsin, which contains 248 amino acid residues, has been determined and the present sequence differs from that recently reported by Ovchinnikov and coworkers with respect to an additional tryptophan and several amino acid assignments.
Abstract: The complete primary structure of the purple membrane protein bacteriorhodopsin, which contains 248 amino acid residues, has been determined. Methods used for separation of the hydrophobic fragments included gel permeation and reverse-phase high-pressure liquid chromatography in organic solvents. The amino acid sequence was determined by a combination of automatic Edman degradation and mass spectrometric methods. The total sequence was derived by ordering of the CNBr fragments on the basis of methionine-containing peptides identified by gas chromatographic mass spectrometry and by analysis of N-bromosuccinimide fragments containing overlaps between CNBr fragments. The present sequence differs from that recently reported by Ovchinnikov and coworkers with respect to an additional tryptophan (position 138) and several amino acid assignments.

349 citations


Journal ArticleDOI
25 Oct 1979-Nature
TL;DR: The results enable us to predict the primary sequence of two related polypeptides from region E1A of human subgroup C adenoviruses, and to study the structure of early ad2 mRNAs at the nucleotide level using molecular cloning procedures to amplify the appropriate mRNA sequences.
Abstract: The papova viruses and the human adenoviruses are widely used as a model system to study cell transformation in vitro. In subgroup C human adenoviruses, fragment HpaI-E, which comprises as little as 4.5% of the adenovirus type 5 (ad5) DNA, is sufficient for transformation of rat embryo cells1. Analysis of messenger RNAs (mRNAs) from the transforming region of adenoviruses type 2 (ad2) has identified several spliced mRN A species2–4. Promoter mapping studies indicate that the leftmost early region contains two separate transcription units, E1A and E1B (ref. 5) (Fig. 1a). Region E1A is approximately equivalent HpaI-E. The complete nucleotide sequence of the HpaI-E fragment of ad5 was recently reported6. However, the spliced nature of early adenovirus mRNAs prevents a prediction of the amino acid sequence of the corresponding polypeptides directly from the DNA sequence. To study the structure of early ad2 mRNAs at the nucleotide level, we have used molecular cloning procedures to amplify the appropriate mRNA sequences. In this report, clones corresponding to the 12S and 13S mRNA from region E1A (Fig. 1c) have been isolated and characterised by hybridisation and sequence analysis. Our results enable us to predict the primary sequence of two related polypeptides from region E1A of human subgroup C adenoviruses.

339 citations


Journal ArticleDOI
09 Aug 1979-Nature
TL;DR: The amino acid sequence of the human fibrinogen α-chain reveals a structure that can be divided into three zones of unique amino acid composition and consists of a remarkable series of internal duplications.
Abstract: The amino acid sequence of the human fibrinogen α-chain reveals a structure that can be divided into three zones of unique amino acid composition. The middle of these contains the two primary α-chain cross-linking acceptor sites and consists of a remarkable series of internal duplications.

285 citations


Journal ArticleDOI
30 Aug 1979-Nature
TL;DR: The amino acid sequence deduced from the DNA indicates that the surface antigen is a protein consisting of 226 amino acids and with a molecular weight of 25,398, and the portion of the gene coding for this protein apparently contains no intervening sequences.
Abstract: DNA extracted from hepatitis B virus Dane particles has been cloned in bacteria using a plasmid vector. A full-length clone has been examined by restriction endonuclease analysis, and the nucleotide sequence of an 892-base pair fragment from cloned hepatitis B viral DNA encoding the surface antigen gene is reported. The amino acid sequence deduced from the DNA indicates that the surface antigen is a protein consisting of 226 amino acids and with a molecular weight of 25,398. The portion of the gene coding for this protein apparently contains no intervening sequences.

281 citations


Journal ArticleDOI
TL;DR: The results suggest that a number of envelope proteins may be exported at a common site, and that there are only a limited number of such sites, and indicate that it is not sufficient to simply attach an amino-terminal signal sequence to a polypeptide to assure its export.
Abstract: We have employed the technique of gene fusion to fuse the LacZ gene encoding the cytoplasmic enzyme beta-galactosidase with the malE gene encoding the periplasmic maltose binding protein (MBP). Strains were obtained which synthesize malE-lacZ hybrid proteins of various sizes. These proteins have, at their amino terminus, a portion of the MBP and at their carboxyl terminus, enzymatically active beta-galactosidase. When the hybrid protein includes only a small, amino-terminal portion of the MBP, the hybrid protein residues in the cytoplasm. When the hybrid protein contains enough of the MBP to include an intact MBP signal sequence, a significant portion of the hybrid protein is found in the cytoplasmic membrane, suggesting that secretion of the hybrid protein has been initiated. However, in no case is the hybrid protein secreted into the periplasm, even when the hybrid protein includes almost the entire MBP. In the latter case, the synthesis and attempted export of the hybrid protein interferes with the export of at least certain normal envelope proteins, which accumulate in the cell in their precursor forms, and the cell dies. These results suggest that a number of envelope proteins may be exported at a common site, and that there are only a limited number of such sites. Also, these results indicate that it is not sufficient to simply attach an amino-terminal signal sequence to a polypeptide to assure its export.

260 citations


Journal ArticleDOI
29 Nov 1979-Nature
TL;DR: A synthetic fowl plague virus (FPV) haemagglutinin gene has been cloned in bacteria and the complete sequence of the RNA gene deduced.
Abstract: A synthetic fowl plague virus (FPV) haemagglutinin gene has been cloned in bacteria and the complete sequence of the RNA gene deduced. It is 1,742 nucleotides long and the mRNA codes for 563 amino acids in an uninterrupted sequence. The nature of some of the important domains in the haemagglutinin has been established, and their structure is discussed in relation to their function. Extensive amino acid sequence homologies exist between FPV and human influenza haemagglutinins.

248 citations


Journal ArticleDOI
TL;DR: Results indicate that Protein S from bovine or human plasma shows many similarities to the other vitamin K dependent proteins present in plasma.
Abstract: Protein S is a vitamin K dependent protein of unknown function, which is present in mammalian plasma. It was isolated from bovine plasma by barium citrate adsorption and elution, ammonium sulfate fractionation, and column chromatography on DEAE-Sephadex, heparin-agarose, and polyhomoarginine-Sepharose. Bovine Protein S (Mr 64,200) is a single-chain glycoprotein with an amino-terminal sequence of Ala-Asn-Thr-Leu-Leu-. It contains 7.0% carbohydrate and 10 residues of gamma-carboxyglutamic acid per mol of protein. Human Protein S (Mr 69,000) is also a single-chain glycoprotein with an amino-terminal sequence of Ala-Asn-Ser-Leu-Leu-. It contains 7.8% carbohydrate and 10 residues of gamma-carboxyglutamic acid per mol of protein. These results indicate that Protein S from bovine or human plasma shows many similarities to the other vitamin K dependent proteins present in plasma.

Journal ArticleDOI
TL;DR: Analysis of nucleotide sequence analysis of the 5' and the 3' terminal of the RNA segments of the genome of fowl plague virus confirms the presence of a common sequence at the 5', 3' terminus of each segment and a complementary sequence which may be important in the control of transcription and replication of the genomes.
Abstract: EXtensive nucleotide sequence analysis of the 5' and the 3' terminal of the RNA segments of the genome of fowl plague virus, an avian strain of influenza virus, confirms the presence of a common sequence at the 5' terminus of each segment and a common sequence at the 3' terminus of each segment. Between the ends of each individual segment there is a complementary sequence which may be important in the control of transcription and replication of the genome. In addition, the probable sites of initiation of translation of fowl plague virus mRNA are indicated along with the corresponding NH2-terminal amino acid sequences of the virus polypeptides.

Journal ArticleDOI
13 Sep 1979-Nature
TL;DR: Ovalbumin is shown to contain an internal rather than an amino-terminal signal sequence, which can be recovered in a tryptic fragment which comprises residues 229–276 of mature ovalbumin and contains a region of striking sequence homology to amino- terminal cleaved signals of two other oviduct secretory proteins.
Abstract: Ovalbumin is shown to contain an internal rather than an amino-terminal signal sequence This internal signal can be recovered in a tryptic fragment which comprises residues 229--276 of mature ovalbumin and contains a region of striking sequence homology to amino-terminal cleaved signals of two other oviduct secretory proteins The isolated tryptic fragment is used as a probe to demonstrate that a signal receptor is present in membrane vesicles derived from the rough but not in those derived from the smooth endoplasmic reticulum

Journal ArticleDOI
TL;DR: A cytoplasmic "petitie" mutant of Saccharomyces cerevisiae (DS200/A1) has been isolated and determined to contain mitochondrial genetic markers in the oxi 1 locus and generates an amino acid sequence consistent with the reported molecular weight and composition of subunit 2 of yeast cytochrome oxidase.


Journal ArticleDOI
TL;DR: The complete amino acid sequence has been derived for human C-reactive protein (CRP) as discussed by the authors, which yielded a unique sequence containing 187 amino acids in a single polypeptide chain.

Journal ArticleDOI
26 Oct 1979-Science
TL;DR: The sequence of the deduced proteins in BK virus shares 73 percent amino acid homology with those in SV40, whereas the DNA sequence ofthe two viruses shares 70 percent homology, suggesting close evolutionary relationship.
Abstract: The complete DNA sequence of the human papovavirus BK is presented. From the 4963 base-pair sequence of BK virus (MM strain), the amino acid sequence of at least five proteins can be deduced: a T antigen and a t antigen, which share amino terminal peptides; proteins VP2 and VP3, which share 232 amino acids; and protein VP1, whose coding sequence overlaps those for VP2 and VP3 by 113 nucleotides but is read in a different frame. The gene loci and the arrangement of genes are strikingly similar in BK virus and simian virus 40 (SV40). The sequence of the deduced proteins in BK virus shares 73 percent amino acid homology with those in SV40, whereas the DNA sequence of the two viruses shares 70 percent homology, suggesting close evolutionary relationship. However, the repeated DNA sequences in the noncoding regions of these viruses are different.

Journal ArticleDOI
15 Oct 1979-Virology
TL;DR: Three monoclonal hybridoma antibodies were used to select a total of 10 antigenic variants of A/Mem/1/71 (H3N2) virus and a dramatic change in antigenicity appeared to be associated with a single change in the amino acid sequence of the large hemagglutinin polypeptide, HA1.

Journal ArticleDOI
TL;DR: Peptide analyses of 32P-labeled intermediate filament subunits suggest that there is considerable similarity in the phosphorylation sites of these proteins, indicating that F-IFP and desmin might be evolutionally related.
Abstract: Extraction of chicken embryo fibroblasts (CEF) or baby hamster kidney (BHK) cells with 1% Triton X-100 and 0.6 M KCl leaves an insoluble cytoskeletal residue composed primarily of the 52,000 Mr subunit of intermediate filaments (F-IFP). In addition, CEF cytoskeletons exhibit a minor component with Mr of 50,000, identified as alpha-desmin, one of the two major isoelectric variants of the intermediate filament subunit from smooth muscle. BHK cytoskeletons contain the 50,000 Mr mammalian desmin variant. Cytoskeletons prepared from chicken embryonic myotubes contain F-IFP and both alpha- and beta-desmin. These data suggest that two distinct 10-nm filament subunits coexist in a single cell. One-dimensional peptide analysis of F-IFP and desmin from avian and mammalian cells reveals significant interspecies homology, as well as homology between F-IFP and desmin from the same species. Peptide analyses of 32P-labeled intermediate filament subunits suggest that there is considerable similarity in the phosphorylation sites of these proteins. These results indicate that F-IFP and desmin might be evolutionally related.

Journal ArticleDOI
TL;DR: Results are consistent with a model in which the protein is anchored to the microvillar membrane by a small hydrophobic domain located within the N-terminal amino acid sequence of the polypeptide chain, and the significance of these results in relation to biosynthesis of the enzyme and assembly in the membrane is discussed.
Abstract: Dipeptidyl peptidase IV was solubilized from the microvillar membrane of pig kidney by Triton X-100. The purified enzyme was homogeneous on polyacrylamide-gel electrophoresis and ultracentrifugation, although immunoelectrophoresis indicated that amino-peptidase M was a minor contaminant. A comparison of the detergent-solubilized and proteinase (autolysis)-solubilized forms of the enzyme was undertaken to elucidate the structure and function of the hydrophobic domain that serves to anchor the protein to the membrane. No differences in catalytic properties, nor in sensitivity to inhibition by di-isopropyl phosphorofluoridate were found. On the other hand, several structural differences could be demonstrated. Both forms were about 130,000 subunit mol.wt., but the detergent form appeared to be larger by no more than about 4,000. Electron microscopy showed both forms to be dimers, and gel filtration revealed a difference in the dimeric mol.wt. of about 38 000, mainly attributable to detergent molecules bound to the hydrophobic domain. Papain converted the detergent form into a hydrophilic form that could not be distinguished in properties from the autolysis form. A hydrophobic peptide of about 3500 mol.wt. was identified as a product of papain treatment. The detergent and proteinase forms differed in primary structure. Partial N-terminal amino acid sequences were shown to be different, and the pattern of release of amino acids from the C-terminus by carboxypeptidase Y was essentially similar. The results are consistent with a model in which the protein is anchored to the microvillar membrane by a small hydrophobic domain located within the N-terminal amino acid sequence of the polypeptide chain. The significance of these results in relation to biosynthesis of the enzyme and assembly in the membrane is discussed.

Journal ArticleDOI
TL;DR: The favin molecule contains residues identical to many of the residues postulated to be involved in sugar binding by Con A, and contains all of the direct metal ligands as well as residues homologous to most of the residue that form the beta-pleated sheets of Con A.
Abstract: We have determined the tentative amino acid sequence of the β chain (Mr 20,000) of the lectin favin. In previous studies, we have shown that the α chain (Mr 5600) of this lectin is homologous to a region in the middle of the concanavalin A (Con A) sequence (residues 70-119). Now we present evidence that the β chain is homologous to two discrete segments of Con A. The homology begins at residue 120 of Con A, extends to the COOH terminus (residue 237) and continues without interruption through the NH2-terminal 69 residues of Con A. Together, the α and β chains of favin account for a polypeptide chain equivalent in size to that of Con A. The comparison of the two proteins thus reveals a circular permutation of extensive homologous sequences. The favin molecule contains residues identical to many of the residues postulated to be involved in sugar binding by Con A, and contains all of the direct metal ligands as well as residues homologous to most of the residues that form the β-pleated sheets of Con A. These homologies suggest that the three-dimensional structures of the two lectins are likely to be very similar. Moreover, favin appears to be even more closely related in primary structure and sugar specificity to the lectins from pea and lentil, raising the possibility that all of these lectins may have structures that resemble Con A. Some of these similarities may also extend to the lectins from soybean, peanut, and red kidney bean, which have different sugar specificities but share sequence homologies with the favin β chain.

Journal ArticleDOI
TL;DR: Comparison of the amino acid sequences of Factor IX, Factor X, and Protein C demonstrates that they are homologous throughout, and their homology with prothrombin is restricted to the amino-terminal region.
Abstract: The amino acid sequence of bovine blood coagulation Factor IX (Christmas Factor) is presented and compared with the sequences of other vitamin K-dependent plasma proteins and pancreatic trypsinogen. The 416-residue sequence of Factor IX was determined largely by automated Edman degradation of two large segments, containing 181 and 235 residues, isolated after activating Factor IX with a protease from Russell's viper venom. Subfragments of the two segments were produced by enzymatic digestion and by chemical cleavage of methionyl, tryptophyl, and asparaginyl-glycyl bonds. Comparison of the amino acid sequences of Factor IX, Factor X, and Protein C demonstrates that they are homologous throughout. Their homology with prothrombin, however, is restricted to the amino-terminal region, which is rich in gamma-carboxyglutamic acid, and the carboxyl-terminal region, which represents the catalytic domain of these proteins and corresponds to that of pancreatic serine proteases.

Journal ArticleDOI
29 Nov 1979-Nature
TL;DR: The cloning of a cDNA prepared from human insulin mRNA and an analysis of the nucleotide sequence of the cloned molecule including the region coding for the prepeptide and portions of the 5′- and the 3′-untranslated regions of the molecule are reported.
Abstract: Insulin consists of two polypeptide chains, A (21 amino acids) and B (30 amino acids), linked by disulphide bonds. Both chains are derived from one precursor, proinsulin, which includes a connecting peptide (C) between the A and B chains, and which is excised before the secretion of insulin from the pancreatic B cells1. The observation that the C-peptide varies between species, in contrast to the highly conserved A and B sequences1–3, is consistent with the theory that it serves a purely structural function in insulin synthesis. During in vitro translation of insulin mRNA, a larger peptide containing about 25 additional residues at the N-terminal end (preproinsulin) is the primary product4–7. The prepeptide is cleaved to leave proinsulin during transport into the endoplasmic reticulum and is thought to direct this process specifically8. Using automated amino acid sequence analysis, the partial amino acid sequences of the prepeptide regions of bovine, rat, sea raven and anglerfish preproinsulin have been established4,5,7. The nucleotide sequences of the cloned cDNA and gene coding for rat insulin I have confirmed the amino acid sequence of rat proinsulin I, and have also predicted the sequence of the prepeptide9–11. Like the prepeptides of other secreted proteins, this prepeptide has a prominent hydrophobic region12. We report here the cloning of a cDNA prepared from human insulin mRNA and an analysis of the nucleotide sequence of the cloned molecule including the region coding for the prepeptide and portions of the 5′- and the 3′-untranslated regions of the molecule. We also compare the structure of the human molecule with the previously reported rat mRNA9–11.

Journal ArticleDOI
TL;DR: The sequence of 102 amino acid residues from the NH2 terminus and that of 39 amino acid residue from the COOH terminus of bacteriorhodopsin have been determined by a judicious combination of mass spectrometric peptide sequencing and automated Edman degradation.
Abstract: The sequence of 102 amino acid residues from the NH2 terminus and that of 39 amino acid residues from the COOH terminus of bacteriorhodopsin have been determined. These results are in agreement with those recently published by Ovchinnikov and coworkers [Ovchinnikov, Y.A., Abdulaey, N.G., Feigina, M.Y., Kiselev, A.V. & Lobanov, N.A. (1977) FEBS Lett. 84, 1-4]. Chymotryptic cleavage of bacteriorhodopsin produced two fragments, C-1 (Mr 19,000) and C-2 (Mr 6900), the latter containing the blocked NH2 terminus (pyroglutamic acid). Further fragmentation with CNBr gave mostly hydrophobic fragments, which were separated by gel permeation and reverse-phase high-pressure liquid chromatography in formic acid/ethanol/water mixtures. The fragments were sequenced by a judicious combination of mass spectrometric peptide sequencing and automated Edman degradation. The C-2 fragments were ordered on the basis of methionine-containing peptides identified by gas chromatographic mass spectrometry, while C-1 and C-2 were arranged by analysis of an overlapping CNBr fragment.

Journal ArticleDOI
TL;DR: Nine peptide fractions were purified to apparent homogeneity judging by thin-layer and ion-exchange column chromatography, and amino acid composition, and Amino acid sequences of the peptides were determined: two were found to be mixtures of peptides and the sequence of another was only partially determined.

Journal ArticleDOI
TL;DR: The nucleotide sequence of a segment of Saccharomyces mtDNA that contains the structural gene for one of the subunits (the dicyclohexylcarbodiimide-binding protein) of the mitochondrial ATPase complex is determined.
Abstract: We have determined the nucleotide sequence of a segment of Saccharomyces mtDNA that contains the structural gene for one of the subunits (the dicyclohexylcarbodiimide-binding protein) of the mitochondrial ATPase complex. The sequence fits the known amino acid sequence of this protein with the exception of one amino acid. Codon usage is biased in favor of A + T-rich codons. On both sides of the gene, the nucleotide sequence contains less than 4% (mol/mol) G + C for at least 180 nucleotides; these A + T sequences show no evidence of internal repetition. The gene and all the A + T-rich sequence preceding the gene are present in a 12S RNA that is the major transcript of this segment of mtDNA. The nature of the sequences responsible for binding ribosomes to mitochondrial mRNA and for termination of RNA synthesis is considered.

Journal ArticleDOI
TL;DR: Comparing the amino acid sequence of thaumatin with that of the other sweet-tasting protein, monellin, the authors have located five sets of identical tripeptides, which might be part of a common antibody recombination site and possibly be involved in the interaction with thesweet-taste receptor.
Abstract: The primary structure of the sweet-tasting protein thaumatin has been elucidated. The protein consists of a single polypeptide chain of 207 residues. The sequence of the N-terminal part of the chain was determined by sequenator analysis. As the protein contains only one methionine residue, it was possible to deduce the N-terminal sequence of the C-terminal cyanogen bromide fragment by automatic sequencing of the cyanogen-bromide-cleaved, succinylated protein. To arrive at the sequence of the whole protein tryptic and Staphylococcus protease peptides, together with chymotryptic peptides and a 2-(2-nitrophenylsulfenyl)-3-methyl-3'-bromoindolenine (BNPS-skatole) fragment were also sequenced. Comparing the amino acid sequence of thaumatin with that of the other sweet-tasting protein, monellin, we have located five sets of identical tripeptides. Since immunological cross-reactivity of thaumatin antibodies with monellin has recently been described, one or more of these tripeptides might be part of a common antibody recombination site and possibly be involved in the interaction with the sweet-taste receptor.

Journal ArticleDOI
TL;DR: In this paper, a deoxyoligonucleotide probe was used to detect gastrin mRNA in poly(A)-enriched RNA preparations from hog antrum, and the nucleotide sequence of the oligonucleotide was deduced from the unique amino acid sequence Trp-Metglu-Glu of gastrin.
Abstract: We have used a specific deoxyoligonucleotide probe to detect gastrin mRNA in poly(A)-enriched RNA preparations from hog antrum. The nucleotide sequence of the oligonucleotide, d(C-T-C-C-T-C-C-A-T-C-C-A), was deduced from the unique amino acid sequence Trp-Met-Glu-Glu of gastrin. When used with hog antral RNA, the dodecanucleotide is an effective primer for the synthesis of gastrin-specific cDNA as judged by nucleotide sequence analysis of cDNA isolated by polyacrylamide gel electrophoresis. We have determined an 81-nucleotide sequence corresponding to the region of the gastrin mRNA that codes for the known amino acid sequence of the G34 progastrin intermediate species, and we have demonstrated the presence of two consecutive basic residues preceding the G34 sequence in the prohormone. Hybridization of gastrin cDNA or synthetic dodecanucleotide to hog antral RNA separated by gel electrophoresis on agarose gels in the presence of methylmercuric hydroxide indicates that the mRNA coding for gastrin is about 620 nucleotides long. These results suggest that the gastrin precursor peptide contains 110-140 amino acids. This method should be of general application for detection and characterization of mRNAs corresponding to proteins of known amino acid sequence.

Journal ArticleDOI
TL;DR: Amino acid analysis and mass spectral analysis of the derivative suggests that X is gamma-glutamylmethylamide, presumptive evidence for an alternative activated center in selected proteins.
Abstract: Methylamine reacts with the plasma protease inhibitor, alpha 2-macroglobulin, to form an irreversible, covalent modification. Quantitation of the reaction indicates 3.9 +/- (SD) 0.4 reactive sites per native tetrameric protein (Mr = 725,000) or one site per subunit. The reaction is selective and specific in that only 1 or 2 labeled peptides are observed on radioautography of peptide maps derived from [14C]methylamine-treated alpha 2-macroglobulin. A single chymotryptic peptide was isolated in 56% overall yield from the labeled protein. The peptide sequence by Edman degradation was found to be Gly-Cys-Gly-Glu-X-Asn-Met-(Val, Leu), in which X was the only radiolabeled phenylthiohydantoin derivative. Amino acid analysis and mass spectral analysis of the derivative suggests that X is gamma-glutamylmethylamide. Because glutamic acid and glutamine residues do not normally react with alkylamines, this work presents presumptive evidence for an alternative activated center in selected proteins.

Journal ArticleDOI
TL;DR: It is concluded that Band 2.1 and possibly some or all of the other, related polypeptides which electrophorese in the 2 region is (are) the spectrin-binding protein(s) of the human erythrocyte.