Showing papers on "Peptide sequence published in 1973"

Complete Amino-Acid Sequence of Actin of Rabbit Skeletal Muscle

Abstract: The complete amino-acid sequence of actin of rabbit skeletal muscle was determined. The actin polypeptide chain is composed of 374 residues, including one residue of the unusual amino acid Nr-methyl histidine, and has a calculated molecular weight of 41,785. The sequence of actin was determined by isolating the peptides produced by cleavage of the protein with cyanogen bromide, determining the sequence of these peptides, and establishing their order within the molecule. This study represents the first complete determination of the aminoacid sequence of a myofibrillar protein. Comparison of this sequence with peptides from actins isolated from different sources indicates that the sequence of actin is highly conserved.

Bovine Parathyroid Hormone: Minimum Chain Length of Synthetic Peptide Required for Biological Activity

Abstract: Several fragments representing progressively shorter segments of the amino terminal region of bovine parathyroid hormone have been prepared by solid-phase peptide synthesis and bioassayed in the in vitro rat kidney adenyl cyclase assay and the in vivo chick hypercalcemia assay. These studies have denned the minimum chain length required for activity. The synthetic amino terminal 1-34 peptide was highly potent (80% on a molar basis of the natural hormone in vitro and 130% in vivo). It was found that deletion of the amino terminal residue (alanine) resulted in a marked decrease in activity and removal of the second residue (valine) at the amino terminus completely abolished activity in both assay systems. Greater shortening was tolerated at the carboxyl terminus. Peptide 1-27 was still active in the in vitro assay; deletion of residue 27 led to loss of biological activity in both assays. (Endocrinology 93: 1349, 1973)

Structure primaire de la caséine β bovine

Abstract: In a previous report [1], we have given the complete primary structure of ϰB1-caseinomacro-peptide which is the soluble COOH-terminal fragment split from bovine ϰB1-casein by rennin. We also reported on the COOH-terminal sequence of the NH2-terminal fragment, the so-called para-ϰ-casein. The present paper deals with the complete amino acid sequence of bovine ϰB-casein, which has now been achieved by establishing the primary structure of para-ϰB-casein of which we discuss the salient features. This work has been reported briefly in a short communication [2]. SCM-para-ϰB-casein and maleyl ϰBCN1, the NH2-terminal cyanogen bromide fragment of ϰB-casein [1], were used as starting material. The tryptic and peptic peptides of SCM-para-ϰB-casein and the chymotryptic peptides of ϰBCN1 were isolated on Dowex 50 and Sephadex G-50 or G-25, and their sequences were determined either partially or completely by using classical methods and in some cases mass spectrometry. All these peptides and a NBS fragment of SCM-para-ϰB-casein have provided all the overlaps needed for the completion of the amino acid sequence of para-ϰB-casein. Para-ϰB-casein is a single polypeptide chain containing 105 amino acid residues: Asp3, Asn4, Thr3, Ser7, PyroGlu1, Glu4, Gln12, Pro12, Gly1, Ala9, Val5, 1/2 Cys2, Met1, Ile6, Leu7, Tyr9, Phe4, Lys6, His3, Trp1, Arg5, and its molecular weight has been calculated to be 12269. The average hydrophobicity, calculated according to Bigelow [3], is 5.48 kJ (1.310 kcal) per residue, and para-ϰB-casein can be therefore considered to be a very hydrophobic molecule. Its net positive charge at pH of native milk (about 6.8) is very close to 4.5. The high content (11.5%) and rather uniform distribution of prolyl residues are incompatible with much α-helical organization of the molecule, as previously shown for ϰ-casein [4]. Both hydrophobic and charged amino acid residues are distributed non-uniformly along the chain. Two regions, 1–24 and 80–105, are hydrophilic: the very hydrophilic former, with NH2-terminal pyroglutamic acid, contains a cysteinyl residue located inside a cluster of eleven ionizable residues including six out of the seven total dicarboxylic amino acids; the 80–105 region, which contains the second cysteinyl residue in position 88, is rather hydrophilic, except at the COOH-terminal end which is hydrophobic in spite of the presence of a cluster of four basic residues. These two hydrophilic regions are very likely to be on the outisde of the molecule and this may favor the formation of intermolecular S-S bonds. The very hydro-phobic central part of the chain, viz., 25–79, where most of the aromatic residues are located, has a para-ϰ-casein-like behaviour in aqueous solution, and it may be responsible for the aggregation ability of para-ϰ-casein. According to the sequence data of both ϰB1-caseinomacropeptide [1] and para-ϰ-casein, it is concluded that bovine ϰB-casein is made up of a single polypeptide chain containing 169 amino acid residues: Asp4, Asn7, Thr14, Ser12, SerP1, PyroGlu1, Glu12, Gln14, Pro20, Gly2, Ala15, Val11, 1/2 Cys2, Met2, Ile13, Leu8, Tyr9, Phe4, Lys9, His3, Trp1, Arg5, with NH2-terminal pyroglutamic acid. However, in accordance with the well-known lability of glutamine residues in NH2-terminal position [5], such a pyroglutamic acid residue may arise from the subsequent cyclisation of a NH2-terminal glutamine residue present originally in native ϰ-casein. The content of proline residues is high (11.8%). The molecular weight of the carbohydrate-free monomer of ϰB-casein is 19023. Its net negative charge at pH of native milk is close to 3.5 and its average hydrophobicity is about 5.37 kJ (1.285 kcal) per residue. We have already reported [6] the location of the two amino acid substitutions differentiating the two known genetic variants : the B variant differs from the A variant by the respective amino acid substitutions Ile 136/Thr and Ala 148/Asp. Tryptic and chymotryptic peptides isolated by Jolles et al. [7] from ϰA-casein correspond obviously to the fragments 11–16, 17–25,31–34, 63–67, 1–10 and 86–105 of ϰ-casein strand, but there is only partial agreement concerning the sequences of amino acid proposed for the last three fragments. More recently, Fiat et al. [8] have studied a short glycopeptide isolated from bovine ϰ-casein, but neither the amino acid sequence nor the location of the phosphate group agree with our results.

The Amino-Acid Sequence of the αA2 Chain of Bovine α-Crystallin

Abstract: Isolated cyanogen bromide fragments of the αB2 chain of α-crystallin contained 67 and 107 residues, respectively. Part of the sequence of the C-terminal fragment was elucidated by Edman and Begg sequenator analysis. Sequences of the tryptic peptides were determined by a combination of various Edman degradation techniques. Overlaps of tryptic peptides were established by selective modification of lysine residues and subsequent tryptic cleavage and by isolation of peptides after hydrolysis with chymotrypsin, thermolysin and a staphylococcal protease. The sequence of the αB2 chain comprises 175 residues corresponding to a molecular weight of 20070. This value is somewhat lower than that assumed hitherto. A high degree of homology between the αB2, and the αA2 chain, the major polypeptides, of bovine α-crystallin was observed.

Complete Amino Acid Sequence of the Mu Heavy Chain of a Human IgM Immunoglobulin

Abstract: The amino acid sequence of the µ, chain of a human IgM immunoglobulin, including the location of all disulfide bridges and oligosaccharides, has been determined. The homology of the constant regions of immunoglobulin µ, γ, α, and e heavy chains reveals evolutionary relationships and suggests that two genes code for each heavy chain.

Studies on Soybean Trypsin Inhibitors

Abstract: For the elucidation of the amino-acid sequence of the carboxyl-terminal region of soybean trypsin inhibitor (Kunitz), fragments C and D were digested with trypsin, and the resulting peptides were separated by ion-exchange chromatography on Dowex 50X2 or by gel nitration on Bio-Gel P-4. Further fractionation and purification of the peptides were performed by ion-exchange chromatography on Dowex 1X2, by gel filtration on Bio-Gel P-2 or by high-voltage paper electrophoresis at pH 1.9 and 3.6. Three peptides were obtained in pure form from fragment C and ten peptides from fragment D, and their amino-acid sequences were determined by the direct Edman method and by carboxy-peptidase digestion technique. Overlapping peptides necessary for the alignment of the tryptic peptides from fragment D were obtained from a chymotryptic hydrolysate of fragment D. Nine main peptides and nine minor peptides were obtained. The amino acid composition and the partial amino-acid sequence of the 18 chymotryptic peptides of fragment D made it possible to establish the amino-acid sequence of the carboxyl-terminal region of the inhibitor. The complete amino-acid sequence of soybean trypsin inhibitor (Kunitz) deduced here was compared with that of Bowman-Birk inhibitor, another well-known soybean proteinase inhibitor.

Motilin, a gastric motor activity stimulating polypeptide: the complete amino acid sequence.

Abstract: Porcine motilin is a 22 amino acid residue polypeptide with the amino acid sequence Phe–Val–Pro–Ile–Phe–Thr–Tyr–Gly–Glu–Leu–Gln–Arg–Met–Glu–Glu–Lys–Glu–Arg–Asn–Lys–Gly–Gln. The calculated molecular...

Automated Edman degradation: the protein sequenator.

Abstract: Publisher Summary The most significant recent development in techniques for the sequence analysis of proteins and peptides is the advent of automated procedures for degradation by the phenylisothiocyanate (PITC) method. The chapter describes the automated procedures in some detail from a practical point of view. In the Edman procedure, the reagent PITC couples with the terminal alpha amino group of a peptide or protein to form a phenylthiocarbamyl (PTC) adduct. Under anhydrous acidic conditions, the N-terminal amino acid residue is selectively cleaved from the peptide chain as a heterocyclic derivative through the attack of the sulfur of the PTC adduct on the carbonyl component of the first peptide bond. The cleaved amino acid derivative is separated from the residual peptide by extraction with an organic solvent and then converted to a more stable isomer prior to identification by one of several possible procedures. The automated Edman procedure is particularly suitable for obtaining long degradations on polypeptides of 60–150 residues. With longer polypeptides, the increased background limits the length of the degradation.

Isolation and Characterisation of Two Calf‐Thymus Chromatin Non‐Histone Proteins with High Contents of Acidic and Basic Amino Acids

Abstract: The group of calf thymus chromatin non-histone proteins which have a high electrophoretic mobility have been fractionated by CM-cellulose ion-exchange chromatography. The fractions thus obtained have been characterised by polyacrylamide gel electrophoresis, amino acid analysis, N-terminal amino acid analysis, and by their molecular weights. Using the CM-cellulose chromatographic method, two proteins which have a high content of basic and acid amino acids have been isolated in a pure form.

The Primary Structure of an Acidic Protein from 50-S Ribosomes of Escherichia coli which is Involved in GTP Hydrolysis Dependent on Elongation Factors G and T

Abstract: The primary structures of the ribosomal proteins A1 (= L7) and A2 (= L12) have been elucidated. Comparison of the two amino acid sequences confirms earlier studies by us (1972) which indicated that the two proteins are identical except that A1 possesses an N-terminal acetyl group. Sequencing of tryptic and chymotryptic peptides was accomplished primarily by automatic solid-phase Edman degradation of 50- to 70-nanomole peptide samples. A large tryptic peptide T1Phe, which could not be sequenced by this method, was fragmented with elastase and its sequence mainly derived by conventional methods. The sequence of the first 51 residues of the nonacetylated A2-protein was obtained by Edman degradation in the Beckman sequencer. A-protein comprises three distinct regions: I (residues 1—55), which is negatively-charged and hydrophobic, II (56—81), which is positively charged, and III (82—120), which is negatively charged and hydrophilic. α-Helix promoting residues are located primarily in regions I and III. ɛ-N-Monomethyllysine, which occurs in 50% of the A1 and A2 chains is located in the more flexible region II at position 81. The distinctive clustering of hydrophobic and charged residues is quite remarkable and suggests that in situ certain of these regions may contain a binding site for components involved in peptide chain elongation.

Amino-Acid Sequence of Porcine Pepsin

Abstract: As the culmination of several years of experiments, we propose a complete amino-acid sequence for porcine pepsin, an enzyme containing 327 amino-acid residues in a single polypeptide chain. In the sequence determination, the enzyme was treated with cyanogen bromide. Five resulting fragments were purified. The amino-acid sequence of four of the fragments accounted for 290 residues. Because the structure of a 37-residue carboxyl-terminal fragment was already known, it was not studied. The alignment of these fragments was determined from the sequence of methionyl-peptides we had previously reported. We also discovered the locations of activesite aspartyl residues, as well as the pairing of the three disulfide bridges. A minor component of commercial crystalline pepsin was found to contain two extra amino-acid residues, Ala-Leu-, at the amino-terminus of the molecule. This minor component was apparently derived from a different site of cleavage during the activation of porcine pepsinogen.

Primary Structure of Somatostatin, A Hypothalamic Peptide That Inhibits the Secretion of Pituitary Growth Hormone

Abstract: Somatostatin, a peptide isolated from ovine hypothalamic tissue that inhibits the release of radioimmunoassayable growth hormone in vitro from rat or human pituitary cells or in vivo in rats, has the primary structure [Formula: see text]. The structure was established by submitting the carboxymethylated peptide, the carboxymethylated tryptic digest, and the chymotryptic digest of the peptide to Edman degradation. Degradation products were analyzed by amino-acid analysis, as well as in some cases by determination of N-termini by dansylation or by determination of phenylthiohydantoins by mass spectrometry.

Biological Activities of Synthetic Peptides Corresponding to Fragments of and to the Entire Sequence of the Vasoactive Intestinal Peptide

Abstract: An octacosapeptide with the entire sequence proposed for the newly isolated vasoactive intestinal polypeptide was synthesized and had the expected biological properties Synthetic peptides corresponding to the C-terminal hendeca-, tetradeca-, pentadeca-, and docosapeptide sequences of the vasoactive intestinal polypeptide showed activities that increased with increasing chain length