Showing papers on "Esterase published in 1977"
TL;DR: It is reported here that several commercial lipases and an esterase also hydrolyse polyesters, and that Rh.
Abstract: INCREASING public concern about the treatment of waste materials has stimulated the study of the biodegradation of synthetic polymers. Among synthetic polymers, aliphatic polyesters are generally known to be susceptible to biological attack1–5, but there are few reports of enzymes involved in their degradation. Bell et al.6 recently showed that the molecular weight of polycaprolactone (PCL) decreases on exposure to the acid protease from Rhizopus chinensis for 6–10 d (decreasing from 13,000 to 10,000). In addition, Tabushi et al.7 have found that polyesters composed of phenyllactic acid and lactic acid are hydrolysed by α-chymotrypsin. We showed previously that a polyester-degrading enzyme from Penicillium sp. strain 14-3, purified to a homogeneous state as exhibited by ultracentrifugal analysis and polyacrylamide gel electrophoresis, has properties resembling lipase8. It was not previously recognised that lipase acts on polyesters. We report here that several commercial lipases and an esterase also hydrolyse polyesters, and that Rh. delemar lipase is capable of hydrolysing various kinds of polyesters.
377 citations
TL;DR: This chapter presents the sequence studies of peptides and proteins using carboxypeptidase Y, an enzyme that removes amino acids as one residue at a time from the carboxyl termini of proteins and peptides.
Abstract: Publisher Summary Carboxypeptidase Y is an enzyme that removes amino acids as one residue at a time from the carboxyl termini of proteins and peptides. This chapter presents the sequence studies of peptides and proteins using carboxypeptidase Y. The assay of peptidase activity is based on the rate of the enzymic hydrolysis of benzyloxycarbonyl-L-phenylalanyl-L-leucine (Z-Phe-Leu). The rate of the reaction can be measured either with the colorimetric ninhydrin method for the estimation of liberated leucine, or spectrophotometrically by the decreases in absorbance at 224 nm. The assay of esterase activity is based on the titrimetric measurement of the release of protons, or upon the spectrophotometric measurement of the change in ultraviolet absorbancy that occurs as a result of the enzymic hydrolysis of Ac-Tyr-OEt. It is found that carboxypeptidase Y hydrolyzes ester and amide substrates of chymotrypsin. The properties of amidase action could be applied to the sequence analyses of peptides with amidated COOH-terminal groups, such as oxytocin and vasopressin.
194 citations
TL;DR: The highly insecticidal α-cyano-3-phenoxybenzyl esters are least susceptible to metabolic attack due to both reduced esterase rates attributable to α substitution in the alcohol moiety and reduced oxidase rates for which no adequate explanation is currently available.
107 citations
TL;DR: In addition to measuring free ligand levels, this assay was used to detect specific binding proteins, e.g., during the purification of antibody to the dinitrophenyl residue, as well as to detect ligand-fluorescent dye conjugates which were substrates for porcine esterase.
67 citations
TL;DR: A method for detecting two alleles at Np-1 (nucleoside phosphorylase) and three allele at Es-10 (esterase 10) from mouse blood by cellulose acetate electrophoresis is described and the allelic constitution at these loci for 44 inbred strains and stocks was determined.
Abstract: A method for detecting two alleles at Np-1 (nucleoside phosphorylase) and three alleles at Es-10 (esterase 10) from mouse blood by cellulose acetate electrophoresis is described. The allelic constitution at these loci for 44 inbred strains and stocks was determined. The location of Np-1 on chromosome 14 was established by backcross experiments in which alleles at Np-1 and Robertsonian translocations were segregating. Es-10 was shown to be linked to Np-1, and the following genetic map of Chr 14 was constructed: centromere-(8.9±4.0 cM)-[Np-1, Wc]-(10.2±1.9 cM)-Es-10-(15.5±3.7 cM)-s. The homologous human loci, NP and ES-D, are not linked.
65 citations
Journal Article•
TL;DR: It is concluded that cell-dependent inhibition is due to the inactivation of an ester enzyme required for phagocytosis which is in or on the neutrophil in an active form, and thus is susceptible to inhibition by the esterase inactivators before contact of the neutphil with thephagocytic stimulus.
Abstract: Diisopropylphosphofluoridate, cyclohexyl alkylphosphonofluoridates, and cyclohexyl phenylalkylphosphonofluoridates, which are potent, irreversible inactivators of serine esterases, inhibit the phagocytosis of opsonized sheep erythrocytes by human neutrophils. Two types of inhibition were observed: a) “cell-dependent” inhibition, which is determined by measuring the ingestion of neutrophils pretreated with the esterase inhibitors and washed; and b) “phagocytosis-dependent” inhibition, which is due to the presence of the inhibitors during phagocytosis. With the cyclohexyl alkylphosphonofluoridates, phagocytosis-dependent inhibition was always greater than cell-dependent inhibition. Cell-dependent inhibition was irreversible and dependent on the duration of the incubation of neutrophils with inhibitor. Both types of inhibition were dependent on the concentration of the inhibitor. Poorly or non-phosphorylating analogues of the cyclohexyl alkylphosphonofluoridates of DFP were not inhibitory; nor did fluoride, the hydrolysis product of these inhibitors, inhibit ingestion under either condition. In addition, neither method of treating the neutrophils resulted in a decrease in neutrophil viability. Furthermore, pretreating the EAC1423 with the inhibitors did not decrease ingestion. We conclude that cell-dependent inhibition is due to the inactivation of an esterase required for phagocytosis which is in or on the neutrophil in an active form, and thus is susceptible to inhibition by the esterase inactivators before contact of the neutrophil with the phagocytic stimulus. Phagocytosis-dependent inhibition is interpreted as being due to inactivation of an esterase required for phagocytosis which is normally in an inactive precursor proesterase form that is activated by the interaction of the neutrophil with the phagocytic stimulus. The distinctly different inhibition profiles of the active and activatable esterases indicate that they are two different activities.
57 citations
TL;DR: In this article, the occurrence of rare variants and genetic polymorphisms of the following 25 systems: (i) Erythrocyte enzymes: acid phosphatase-1, adenosine deaminase, adenylate kinase-k, carbonic anhydrase-2, esterase A1,2,3, estersterase D, galactose-1-phosphate uridyltransferase, isocitrate dehydrogenase, lactate dehydrogenases, malate deodorizerase, nucleoside phosphory
Abstract: Blood samples from 509 Macushi and 623 Wapishana Amerindians of Northern Brazil and Southern Guyana have been analyzed with reference to the occurrence of rare variants and genetic polymorphisms of the following 25 systems: (i) Erythrocyte enzymes: acid phosphatase-1, adenosine deaminase, adenylate kinase-k, carbonic anhydrase-1, carbonic anhydrase-2, esterase A1,2,3, esterase D, galactose-1-phosphate uridyltransferase, isocitrate dehydrogenase, lactate dehydrogenase, malate dehydrogenase, nucleoside phosphorylase, peptidase A, peptidase B, phosphoglucomutase 1, phosphoglucomutase 2, phosphogluconate dehydrogenase, phosphohexoseisomerase, triosephosphate isomerase and (ii) Serum proteins: albumin, ceruloplasmin, haptoglobin, hemoglobin A, hemoglobin A2 and transferrin. Fifteen different rare variants were detected, involving 11 of these systems. In addition, a previously undescribed variant of ESA1,2,3 which achieves polymorphic proportions in both these tribes is described. Excluding this variant, the frequency of rare variants is 1.1/1000 in 12510 determinations in the Macushi and 4.7/1000 in 15 396 determinations in the Wapishana. The ESA1,2,3, polymorphism was not observed in 382 Makiritare, 232 Yanomama, 146 Piaroa, 404 Cayapo, 190 Kraho and 112 Moro. Irregularities in the intratribal distribution of this polymorphism in the Macushi and Wapishana render a decision as to the tribe of origin impossible at present. Gene frequencies are also given for previosly described polymorphisms of 5 systems: haptoglobin, phosphoglucomutase 1, erythrocyte acid phosphatase, esterase D, and galactose-1-phosphate-uridyl-transferase.
47 citations
42 citations
TL;DR: The Lys-plasmin-streptokinase complex, and streptokerase were the least active of the activator species and were approximately equal in their activator activities.
41 citations
TL;DR: The kinetics of the NAD+-dependent oxidation of aldehydes, catalysed by aldehyde dehydrogenase purified from sheep liver mitochondria, were studied in detail and the mechanistic implications of the above behaviour are discussed.
Abstract: The kinetics of the NAD+-dependent oxidation of aldehydes, catalysed by aldehyde dehydrogenase purified from sheep liver mitochondria, were studied in detail. Lag phases were observed in the assays, the length of which were dependent on the enzyme concentration. The measured rates after the lag phase was over were directly proportional to the enzyme concentration. If enzyme was preincubated with NAD+, the lag phase was eliminated. Double-reciprocal plots with aldehyde as the variable substrate were non-linear, showing marked substrate activation. With NAD+ as the variable substrate, double-reciprocal plots were linear, and apparently parallel. Double-reciprocal plots with enzyme modified with disulfiram (tetraethylthiuram disulphide) or iodoacetamide, such that at pH 8.0 the activity was decreased to 50% of the control value, showed no substrate activation, and the plots were linear. At pH 7.0, the kinetic parameters Vmax. and Km NAD+- for the oxidation of acetaldehyde and butyraldehyde by the native enzyme are almost identical. Formaldehyde and propionaldehyde show the same apparent maximum rate. Aldehyde dehydrogenase is able to catalyse the hydrolysis of p-nitrophenyl esters. This esterase activity was stimulated by both NAD+ and NADH, the maximum rate for the NAD+ stimulated esterase reaction being roughly equal to the maximum rate for the oxidation of aldehydes. The mechanistic implications of the above behaviour are discussed.
40 citations
TL;DR: A further ester enzyme, esterase 11, which exhibits a polymorphism detectable by electrophoresis, has been observed in the house mouse, Mus musculus, and in F1 hybrids (IS/Cam×C57 BL/Gr), the phenotype shown corresponds to a mixture of the two parental phenotypes.
Abstract: A further esterase, esterase 11, which exhibits a polymorphism detectable by electrophoresis, has been observed in the house mouse, Mus musculus. In 15 inbred strains and two outbred strains, the ES-11A phenotype has been found, composed of two bands of enzyme activity of greater anodal electrophoretic mobility than the two bands of the ES-11B phenotype found in one inbred strain, one wild stock, and 101 wild mice. In F1 hybrids (IS/Cam×C57 BL/Gr), the phenotype shown corresponds to a mixture of the two parental phenotypes. In backcrosses, ES-11 segregates as an autosomal gene, designated Es-11, closely linked to Es-2 and Es-5 on chromosome 8.
TL;DR: The peptide 'map' of the tryptic digest of carboxypeptidase B1 contained more peptides than did that of form B2, and the pH optimum of the cleavage of the peptide substrate hippurylarginine and the ester substrate hipparylargininic acid were similar for both enzymes.
Abstract: Carboxypeptidase B of the human pancreas was purified by chromatography on DEAE-cellulose and CM-cellulose columns. Two forms of the enzyme, named carboxypeptidase B1 and B2, were separated. They have similar mol.wts. (34250 +/- 590) as established by polyacrylamide-gel disc electrophoresis and by gel filtration. Carboxypeptidase B2 migrates further towards the anode in disc electrophoresis. When the amino acid content of the enzymes was analysed, carboxypeptidase B2 had four more glycine and three more aspartic acid residues than had form B1. The amino acid sequence of the human carboxypeptidase B1 differs from that of the bovine enzyme only in two places in the N-terminal 20-amino-acid sequence. The N-terminal amino acid in carboxypeptidase B1 and B2 is alanine. The peptide ‘map’ of the tryptic digest of carboxypeptidase B1 contained more peptides than did that of form B2. The Km, the Vmax. and the pH optimum of the cleavage of the peptide substrate hippurylarginine and the ester substrate hippurylargininic acid were similar for both enzymes. CoCl2 accelerated the peptidase activity, and cadmium acetate enhanced the esterase activity, of human carboxypeptidases B1 and B2. Urea and sodium dodecyl sulphate inhibited the enzymes.
TL;DR: It is highly statistically significant that NADP-dependent dehydrogenases and esterases are polymorphic but representatives of several other major classes of enzymes are not.
Abstract: In contrast to other reports, it is found that the sheep has approximately as much enzyme variation as man.
TL;DR: Among 1, 095 strains of native cultivars observed, eleven out of the twelve expected zymograrns were found and no other pattern appeared and the isoenzymic genotypes well corresponded to conventional varietal groups.
Abstract: Esterase isoenzymes in the leaf blade were observed in a large number of rice strains and hybrid plants between certain parental strains. The slowest isoenzyme band, 1A, was specified by a dominant allele at the esterase locus Est1 The second band-group, 6A and 7A, was controlled by codominant alleles. Est2S and Est2F at Est2, where was also found a null allele. The third band-group, 12A and 13A, was controlled by codo-minant alleles, Est3S and Est3F at Est3. Among the three loci, no linkage relation was indicated between Est1 and Est2 and between Est2 and Est3. These loci involving five dominant and two null alleles are expected to produce twelve zymograms. Among 1, 095 strains of native cultivars observed, eleven out of the twelve expected zymograrns were found and no other pattern appeared. The isoenzymic genotypes well corresponded to conventional varietal groups.
TL;DR: The neutral protease activity copurified with esterase activity during ammonium sulfate fractionation, chromatography on diethylaminoethyl-cellulose, and gel filtration on Sephadex G-150 and was sensitive to ethylenediaminetetraacetate and was significantly activated by divalent ions.
Abstract: Saccharomycopsis lipolytica 37-1 produced two inducible extracellular proteases, one under neutral or alkaline growth conditions and the second under acid conditions. Secretion of the neutral protease was repressed in the presence of glycerol or glucose, both of which supported rapid growth of the organism. Ammonium ions also repressed the secretion of the enzyme. The neutral protease activity copurified with esterase activity during ammonium sulfate fractionation, chromatography on diethylaminoethyl-cellulose, and gel filtration on Sephadex G-150. The molecular weight of the enzyme was estimated to be 42,000 by sucrose density gradient centrifugation and 38,500 by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The purified enzyme had a pH optimum of 6.8. Phenylmethylsulfonylfluoride inhibited both protease and esterase activities, indicating the presence of a serine residue in the active center. Protease, but not esterase, activity was sensitive to ethylenediaminetetraacetate and was significantly activated by divalent ions. Dithiothreitol inhibited both protease and esterase activities, indicating the presence of a critical disulfide bridge. The enzyme hydrolyzed casein (Km = 25.6 μM) and hemoglobin as well as the nitrophenyl esters of tyrosine (Km = 2.4 mM), glycine, tryptophan, and phenylalanine.
TL;DR: Starch gel electrophoresis was employed to study the differences between the esterase and cathodal peroxidase isozyme patterns of 40 broad bean (Vicia faba L.) cultivars, finding that a large proportion of the cultivars could be completely differentiated using both of the isozyme systems.
Abstract: With the increasing rate of new cultivar production for different crop plants, there is great need for methods of identifying each cultivar discriminatingly. Starch gel electrophoresis was employed to study the differences between the esterase and cathodal peroxidase isozyme patterns of 40 broad bean (Vicia faba L.) cultivars. A total of 10 and 17 medium to darkly stained bands were obtained for esterase and peroxidase systems, respectively. Bands from each enzyme system could be gropuped into three zones. Bands belonging to zone 1 of esterase (E1) and zones 2 and 3 of peroxidase (P2 and P3) were quite distinct, stained intensely, and were especially useful for identification purposes.
TL;DR: The results suggest that LIF may act as a serine esterase or aserine protease, or both of these, and that this putative enzyme is present in an activated form in supernatants from mitogen‐stimulated mononuclear cells.
Abstract: The activity of leukocyte migration inhibitory factor (LIF) obtained from Sephadex-G-100-chromatographed supernatants of concanavalin-A-stimulated human lymphocytes was suppressed by two synthetic serine esterase and serine protease inhibitors (di-isopropylfluorophosphate (DFP) and phenylmethylfulfonyl fluoride (PMSF)). LIF activity was also reduced by the naturally occurring protease inhibitors soybean trypsin inhibitor and aprotinin. The observed effect of DFP and PMSF was irreversible, since elimination of the inhibitors by dialysis did not restore LIF activity. The effect of PMSF was dose-, time-, and temperature-dependent, and hydrolytic products of PMSF as well as sodium fluoride were inactive in blocking LIF. These results suggest that LIF may act as a serine esterase or a serine protease, or both of these, and that this putative enzyme is present in an activated form in supernatants from mitogen-stimulated mononuclear cells.
01 Jan 1977
TL;DR: The esterases found in whole saliva are suggested to be derived from the cells of the tissue in the oral cavity, and their origin is indicated by comparison between isolectrophoretic esterase patterns of whole saliva, submandibular saliva, gingival biopsy and fibroblast culture.
Abstract: Whole saliva of 59 healthy persons was used for determination of esterase activity. The pattern of esterase was studied by means of isoelectrofocusing on thin-layer acrylamide gels. The esterases found in whole saliva are suggested to be derived from the cells of the tissue in the oral cavity. This origin is indicated (e.g.) by comparison between isolectrophoretic esterase patterns of whole saliva, submandibular saliva, gingival biopsy and fibroblast culture. Antisera against partially purified saliva esterases were produced in rabbits. These sera, used in immunoelectro-osmophoresis, gave esterase-active immunoprecipitate against whole saliva, the water-soluble materials of disrupted gingival biopsy and fibroblast culture, but not against the material of the bacteria, Streptococcus sanguis, Strptococcus mutans, Streptococcus mitis, Actinomyces viscosus and Lactobacillus fermentum.
TL;DR: A survey of esterases in field populations of the peach-potato aphid, Myzus persicae was made during the spring of 1975, and another variant with threefold (approximately) more esterase activity appeared to be replacing the resistant variant in populations which have been treated twice with OP.
Abstract: SUMMARY
A survey of esterases in field populations of the peach-potato aphid, Myzus persicae was made during the spring of 1975. Assay was by electrophoresis of single aphid homogenates, and the known association between the activity of an esterase and resistance to organophosphorus insecticide (OP) was used to infer resistance in field populations. The resistant variant replaced the susceptible in populations which had been treated with OP and another variant with threefold (approximately) more esterase activity appeared to be replacing the resistant variant in populations which have been treated twice with OP. The significance of this for control of M. persicae is discussed. Differences in resistance between aphids in different parts of the same field, and the widespread association of these esterase variants in favoured combinations with two electrophoretic variants at another locus have also been investigated.
TL;DR: Monoacylglycerol lipase differed immunologically from two kinds of microsomal esterase and inhibited the enzyme activity completely, and showed a little hydrolytic activity on short chain triacyl Glycerol such as tributyryl glycerol, but did not hydrolyze long chain triACYlglycersol.
TL;DR: The substrate specificities of two different molecular sizes of cathepsin A, A,L (large form) and A,S (small form), for synthetic substrates were examined kinetically and suggested that the peptidase and esterase activities of the enzymes are both catalyzed by the same site of the enzyme molecule.
Abstract: The substrate specificities of two different molecular sizes of cathepsin A, A,L (large form) and A,S (small form), for synthetic substrates were examined kinetically. Both enzymes showed a similar broad substrate specificity against various acyl dipeptides, amino acid esters, and amino acid amides. Z-Phe-Ala and Ac-Phe-OEt were good substrates. Peptides containing hydrophobic amino acids were hydrolyzed rapidly. The presence of hydrophobic amino acid residues, not only at the C-terminal position but also at the second position and probably the third position from the C-terminal, resulted in an increase in the rate of hydrolysis. Peptides containing glycine and proline were hydrolyzed slowly. Inhibition studies with Z-D-Phe-D-Ala and Z-Phe suggested that the peptidase and esterase activities of the enzymes are both catalyzed by the same site of the enzyme molecule, but it remains to be elucidated whether or not the binding sites for peptides and esters are the same.
TL;DR: Results support the suggestion that the rate of hydrolysis may be related to desirable prolongation of action of ester prodrugs of apomorphine.
TL;DR: The divergences in electrophoretic distribution of bands E3 and E4 were sufficient to recognize the subgenera of most of the Salmonella strains analysed and were closely related in terms of their esterase profiles.
Abstract: SUMMARY: Esterases of 85 strains of the four biochemically-defined subgenera of Salmonella, when analysed by the acrylamide-agarose zymogram technique using several synthetic substrates, gave four principal bands (E1, E2, E3, E4) and two minor ones. The E1 esterase band hydrolysed α-naphthyl acetate, whereas the E2 band hydrolysed β-naphthyl acetate. These bands were resistant to di-isofluoropropyl phosphate (DFP) and their electrophoretic distribution among the strains occurred within a relatively small MF
range, MF
being the distance moved by the esterase band as a percentage of the distance moved by the dye front. The E3 band hydrolysed α-naphthyl acetate and α-naphthyl butyrate and, to a lesser degree, β-naphthyl esters, whereas the E4 band hydrolysed α-naphthyl acetate. These bands were sensitive to DFP and their electrophoretic distribution among the strains occurred in a wide MF
range. All Salmonella strains were closely related in terms of their esterase profiles. However, the divergences in electrophoretic distribution of bands E3 and E4 were sufficient to recognize the subgenera of most of the Salmonella strains analysed.
TL;DR: Detergent extracts of liver microsomes from drug-treated rats were analyzed semiquantitatively in crossed immunoelectrophoresis in combination with a zymogram technique for nonspecific esterase activity and it was concluded that this ester enzyme-active antigen is located on the cytoplasmic side of the microsomal vesicles.
TL;DR: An enzyme hydrolyzing methylparaoxon in vitro in an organophosphorus-resistant strain of the peach potato aphid is present in the same electrophoretic fraction as a carboxylesterase (esterase 2) which has previously been shown to have characteristically increased activity in organoph phosphorus resistant strains of this aphid.
TL;DR: In this paper, 2-hydroxy-5-nitrobenzyl bromide was applied to thrombin at pH 4.0 to give a modified enzyme which possessed 20% of the fibrinogen clotting activity and 80% of esterase activity compared to a control preparation.
TL;DR: The results show the existence of two isozymes of esterase in the microsomal fraction, which contains about 95% of the ester enzyme activity but little triacylglycerol lipase activity.
TL;DR: It seems that in all tissues of the F1 hybrid there is expression of all the esterase genes from the platyfish, and this is discussed in comparison to those from other studies on teleost esterases.
Abstract: Tissue-specific esterases of the xiphophorine fishes Platypoecilus maculatus (platyfish), Xiphophorus helleri (swordtail), and their F1 hybrid have been analyzed using disc electrophoresis. Seven esterase zones (resolved into a maximum of nine bands) exist in these fishes, and these have been classified by employing specific inhibitors. Five of the seven zones, EST-1, EST-2, EST-5, EST-6, and EST-7, appeared to be carboxylesterases; while the two remaining zones, EST-3 and EST-4, were classified as cholinesterases. In the liver of the platyfish, all seven esterase zones were detected, while the liver of the swordtail exhibited only five esterase zones. EST-1 and EST-3 were lacking in the liver tissue of the swordtail. All seven esterase loci were expressed in the liver tissue of the F1 hybrid. The reciprocal crosses gave the same results. In the fin, skin, skeletal muscle, and eye tissues from all three genotypes, three major esterase zones, EST-2, EST-5, and EST-7, were detected. In addition, EST-1 was frequently detected in all these tissues of the platyfish and the F1, but was lacking in the swordtail. Serum from three genotypes showed one prominent esterase zone, EST-5; however, trace activity of EST-2 and EST-7 zones could also be detected. It seems that in all tissues of the F1 hybrid there is expression of all the esterase genes from the platyfish. The results of the present study are discussed in comparison to those from other studies on teleost esterases.
TL;DR: The results demonstrate that the duplication of chromosomes by autotetraploidy brought about quantitative and, in certain instances, qualitative differences in the esterase zymogram and protein profile.
Abstract: The esterase isozymes and protein profiles of the diploid and corresponding autotetraploid strains of some wild and cultivated plants were investigated using the gel isoelectrofocusing method.The esterase zymogram changed with the age of seedlings. The diploid and autotetraploid strains of Oryza sativa cv. Shinriki-mochi had the same zymogram in one day-old seedlings, but their zymograms showed clear differences in older seedlings.Comparison of the diploid and corresponding autotetraploid strains revealed that three different relationships exist among the zymograms. In the first group, the diploids and autotetraploids had the same pI bands with the same activities. In the second they had the same pI bands, but the activities of some bands were higher in the autotetraploids than in the diploids. In the third group the diploids and autotetraploids had some bands of different pI values. Frequencies of the strains belonging to the three groups were 35, 50 and 15%, respectively.In the protein profile, the same relationships were found in the diploids and their autotetraploids, as were found in the esterase zymogram. The results demonstrate that the duplication of chromosomes by autotetraploidy brought about quantitative and, in certain instances, qualitative differences in the esterase zymogram and protein profile.