scholarly journals A trypsin and chymotrypsin inhibitor from chick peas (Cicer arietinum)

1976 ◽  
Vol 157 (3) ◽  
pp. 745-751 ◽  
Author(s):  
P Smirnoff ◽  
S Khalef ◽  
Y Birk ◽  
S W Applebaum
Keyword(s):  
Molecular Weight ◽  
Inhibitory Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Limited Proteolysis ◽  
Polyacrylamide Gel ◽  
Molar Ratio ◽  
Chymotrypsin Inhibitor ◽  
Trypsin Inhibitory Activity ◽  
Hydrolysis Of

1. A trypsin and chymotrypsin inhibitor was isolated by extraction of chick-pea meal at pH8.3, followed by (NH4)2SO4 precipitation and successive column chromatography on CM-cellulose and calcium phosphate (hydroxyapatite). 2. The inhibitor was pure by polyacrylamide-gel and cellulose acetate electrophoresis and by isoelectric focusing in polyacrylamide gels. 3. The inhibitor had a molecular weight of approx. 10000 as determined by ultracentrifugation and by polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. A molecular weight of 8300 was resolved from its amino acid composition. 4. The inhibitor formed complexes with trypsin and chymotrypsin at molar ratios of 1:1. 5. Limited proteolysis of the inhibitor with trypsin at pH3.75 resulted in hydrolysis of a single-Lys-X-bond and in consequent loss of 85% of the trypsin inhibitory activity and 60% of the chymotrypsin inhibitory activity. Limited proteolysis of the inhibitor with chymotrypsin at pH3.75 resulted in hydrolysis of a single-Tyr-X-bond and in consequent loss of 70% of the trypsin inhibitory activity and in complete loss of the chymotrypsin inhibitory activity. 6. Cleavage of the inhibitor with CNBr followed by pepsin and consequent separation of the products on a Bio Gel P-10 column, yielded two active fragments, A and B. Fragment A inhibited trypsin but not chymotrypsin, and fragment B inhibited chymotrypsin but not trypsin. The specific trypsin inhibitory activity, on a molar ratio, of fragment A was twice that of the native inhibitor, suggesting the unmasking of another trypsin inhibitory site as a result of the cleavage. On the other hand, the specific chymotrypsin inhibitory activity of fragment B was about one-half of that of the native inhibitor, indicating the occurrence of a possible conformational change.

Purification and partial characterization of cysteine-glutamate transaminase from rat liver

1977 ◽  
Vol 55 (9) ◽  
pp. 958-964 ◽  
Author(s):  
M. P. C. Ip ◽  
R. J. Thibert ◽  
D. E. Schmidt Jr.
Keyword(s):  
Molecular Weight ◽  
Rat Liver ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Liver Homogenate ◽  
Polyacrylamide Gel ◽  
Gel Chromatography ◽  
Labile Hydrogen ◽  
Apparent Homogeneity

Cysteine-glutamate transaminase (cysteine aminotransferase; EC 2.6.1.3) has been purified 149-fold to an apparent homogeneity giving a specific activity of 2.09 IU per milligram of protein with an overall yield of 15%. The isolation procedures involve the preliminary separation of a crude rat liver homogenate which was submitted sequentially to ammonium sulfate fractionation, TEAE-cellulose column chromatography, ultrafiltration, and isoelectrofocusing. The final product was homogenous when examined by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS). A minimal molecular weight of 83 500 was determined by Sephadex gel chromatography. The molecular weight as estimated by polyacrylamide gel electrophoresis in the presence of SDS was 84 000. The purified enzyme exhibited a pH optimum at 8.2 with cysteine and α-ketoglutarate as substrates. The enzyme is inactivated slowly when kept frozen and is completely inactivated if left at room temperature for 1 h. The enzyme does not catalyze the transamination of α-methyl-DL-cysteine, which, when present to a final concentration of 10 mM, exhibits a 23.2% inhibition of transamination of 30 mM of cysteine. The mechanism apparently resembles that of aspartate-glutamate transaminase (EC 2.6.1.1) in which the presence of a labile hydrogen on the alpha-carbon in the substrate is one of the strict requirements.

Biosynthesis of glucosyl monophosphoryl undecaprenol and its role in lipoteichoic acid biosynthesis

1982 ◽  
Vol 152 (2) ◽  
pp. 616-625
Author(s):  
D J Mancuso ◽  
T H Chiu
Keyword(s):  
Thin Layer ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Deae Cellulose ◽  
Lipoteichoic Acid ◽  
Molar Ratio ◽  
Streptococcus Sanguis ◽  
Chromatographic Profile ◽  
Hydrolysis Of ◽  
Cellulose Column

A glucophospholipid was detected in an incubation mixture containing UDP-glucose, MgCl2, ATP, and a particulate enzyme prepared from Streptococcus sanguis. The synthesis of this lipid was inhibited strongly by UDP and moderately by UMP. The molar ratio of glucose to phosphate in the purified lipid was found to be 1:1. Glucose and glucose 1-phosphate were released by mild alkaline hydrolysis of the glucophospholipid. The lipid produced by mild acid degradation of the purified lipid yielded a thin-layer chromatographic profile similar to that of acid-treated undecaprenol. One of the minor components exhibited the same mobility as untreated undecaprenol. To characterize further the lipid moiety of the glucophospholipid, a polyisoprenol was purified from the neutral lipid of S. sanguis. The polyisoprenol was converted in the presence of ATP, UDP-glucose, and the particulate enzyme into a lipid which exhibited the same thin-layer chromatographic mobility as the glucophospholipid. The structure of the polyisoprenol was determined by nuclear magnetic resonance and mass spectrometry to be an undecaprenol with an internal cis-trans ratio of 7:2. These results indicate that the glucophospholipid is glucosyl monophosphoryl undecaprenol. The glucosyl moiety of the glucophospholipid was shown to be incorporated in the presence of the particulate enzyme into a macromolecule which was characterized as a lipoteichoic acid by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and DEAE-cellulose column chromatography. This result indicates that glucosyl monophosphoryl undecaprenol is the direct glucosyl donor in the synthesis of lipoteichoic acid.

scholarly journals Purification, characterization and radioimmunoassay of adenosine deaminase from human leukaemic granulocytes

1981 ◽  
Vol 195 (2) ◽  
pp. 389-397 ◽  
Author(s):  
D A Wiginton ◽  
M S Coleman ◽  
J J Hutton
Keyword(s):  
Molecular Weight ◽  
Adenosine Deaminase ◽  
Gel Electrophoresis ◽  
Specific Activity ◽  
Periodic Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Periodic Acid Schiff ◽  
Apparent Homogeneity

Adenosine deaminase was purified 3038-fold to apparent homogeneity from human leukaemic granulocytes by adenosine affinity chromatography. The purified enzyme has a specific activity of 486 mumol/min per mg of protein at 35 degrees C. It exhibits a single band when subjected to sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, non-denaturing polyacrylamide-gel electrophoresis and isoelectric focusing. The pI is 4.4. The enzyme is a monomeric protein of molecular weight 44000. Both electrophoretic behaviour and molecular weight differ from those of the low-molecular-weight adenosine deaminase purified from human erythrocytes. Its amino acid composition is reported. Tests with periodic acid-Schiff reagent for associated carbohydrate are negative. Of the large group of physiological compounds tested as potential effectors, none has a significant effect. The enzyme is specific for adenosine and deoxyadenosine, with Km values of 48 microM and 34 microM respectively. There are no significant differences in enzyme function on the two substrates. erythro-9-(2-Hydroxy non-3-yl) adenine is a competitive inhibitor, with Ki 15 nM. Deoxycoformycin inhibits deamination of both adenosine and deoxyadenosine, with an apparent Ki of 60-90 pM. A specific antibody was developed against the purified enzyme, and a sensitive radioimmunoassay for adenosine deaminase protein is described.

scholarly journals Purification and properties of adenylyl sulphate:ammonia adenylyltransferase from Chlorella catalysing the formation of adenosine 5′-phosphoramidate from adenosine 5′-phosphosulphate and ammonia

1981 ◽  
Vol 195 (3) ◽  
pp. 545-560 ◽  
Author(s):  
Heinz Fankhauser ◽  
Jerome A. Schiff ◽  
Leonard J. Garber
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Deae Cellulose ◽  
Low Ph ◽  
Polyacrylamide Gel ◽  
Ph Optimum ◽  
Unknown Compound ◽  
Reactive Blue 2

Extracts of Chlorella pyrenoidosa, Euglena gracilis var. bacillaris, spinach, barley, Dictyostelium discoideum and Escherichia coli form an unknown compound enzymically from adenosine 5′-phosphosulphate in the presence of ammonia. This unknown compound shares the following properties with adenosine 5′-phosphoramidate: molar proportions of constituent parts (1 adenine:1 ribose:1 phosphate:1 ammonia released at low pH), co-electrophoresis in all buffers tested including borate, formation of AMP at low pH through release of ammonia, mass and i.r. spectra and conversion into 5′-AMP by phosphodiesterase. This unknown compound therefore appears to be identical with adenosine 5′-phosphoramidate. The enzyme that catalyses the formation of adenosine 5′-phosphoramidate from ammonia and adenosine 5′-phosphosulphate was purified 1800-fold (to homogeneity) from Chlorella by using (NH4)2SO4 precipitation and DEAE-cellulose, Sephadex and Reactive Blue 2–agarose chromatography. The purified enzyme shows one band of protein, coincident with activity, at a position corresponding to 60000–65000 molecular weight, on polyacrylamide-gel electrophoresis, and yields three subunits on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of 26000, 21000 and 17000 molecular weight, consistent with a molecular weight of 64000 for the native enzyme. Isoelectrofocusing yields one band of pI4.2. The pH optimum of the enzyme-catalysed reaction is 8.8. ATP, ADP or adenosine 3′-phosphate 5′-phosphosulphate will not replace adenosine 5′-phosphosulphate, and the apparent Km for the last-mentioned compound is 0.82mm. The apparent Km for ammonia (assuming NH3 to be the active species) is about 10mm. A large variety of primary, secondary and tertiary amines or amides will not replace ammonia. One mol.prop. of adenosine 5′-phosphosulphate reacts with 1 mol.prop. of ammonia to yield 1 mol.prop. each of adenosine 5′-phosphoramidate and sulphate; no AMP is found. The highly purified enzyme does not catalyse any of the known reactions of adenosine 5′-phosphosulphate, including those catalysed by ATP sulphurylase, adenosine 5′-phosphosulphate kinase, adenosine 5′-phosphosulphate sulphotransferase or ADP sulphurylase. Adenosine 5′-phosphoramidate is found in old samples of the ammonium salt of adenosine 5′-phosphosulphate and can be formed non-enzymically if adenosine 5′-phosphosulphate and ammonia are boiled. In the non-enzymic reaction both adenosine 5′-phosphoramidate and AMP are formed. Thus the enzyme forms adenosine 5′-phosphoramidate by selectively speeding up an already favoured reaction.

scholarly journals Mapping of the genes controlling high-molecular-weight glutelin subunits of rye on the long arm of chromosome 1R

1984 ◽  
Vol 44 (2) ◽  
pp. 117-123 ◽  
Author(s):  
N. K. Singh ◽  
K. W. Shepherd
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Translocation Line ◽  
Sds Page ◽  
Chromosome 1R

SUMMARYThe gene(s) controlling the high-molecular-weight glutelin subunits in rye (designated as Glu-Rl) was mapped with respect to the centromere using a 1RL-1DS wheat-rye translocation line and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Analysis of 479 seeds from test-crosses between a 1R/1RL-1DS heterozygote and the cultivar India 115, revealed 14·6% aneuploid and 3·95% recombinant progeny. Excluding the aneuploids, this locus was calculated to be 4·65 ± 1·04 cM from the centromere on the long arm of chromosome 1R, which is comparable to the position of the homoeologous loci in wheat and barley.

scholarly journals Purification and subunit structure of legumin of Vicia faba L. (broad bean)

1974 ◽  
Vol 141 (2) ◽  
pp. 413-418 ◽  
Author(s):  
David J. Wright ◽  
Donald Boulter
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Broad Bean ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Exchange Chromatography ◽  
Polyacrylamide Gel ◽  
Subunit Structure ◽  
Isoelectric Precipitation ◽  
Molecular Weights

Zonal isoelectric precipitation was shown to be an effective method for the preparation of legumin which was homogeneous as judged by ultracentrifugation and polyacrylamide-gel electrophoresis. The subunit structure of legumin was investigated by preparative sodium dodecyl sulphate–polyacrylamide-gel electrophoresis and ion-exchange chromatography in urea. Five distinct subunits, of which two were acidic (α) and had a molecular weight of 37000, and three were basic (β) with molecular weights of 20100, 20900 and 23800, were identified. The α and β subunits were present in equimolar amounts in the legumin molecule and, in view of this and molecular-weight considerations, an α6β6 subunit model was proposed for legumin.

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