Purification and characterization of trypsin from the Greenland cod (Gadus ogac). 1. Kinetic and thermodynamic characteristics

1984 ◽  
Vol 62 (9) ◽  
pp. 894-900 ◽  
Author(s):  
B. K. Simpson ◽  
N. F. Haard
Keyword(s):  
Trypsin Inhibitor ◽  
Polyacrylamide Gel Electrophoresis ◽  
Thermodynamic Characteristics ◽  
Soybean Trypsin Inhibitor ◽  
Turnover Number ◽  
Bovine Trypsin ◽  
Hydrolytic Reaction ◽  
Entropy Of Activation ◽  
Sepharose 4B ◽  
Hydrolysis Of

Trypsinogen was isolated from the pyloric ceca of Greenland cod by ammonium sulfate fractionation followed by acetone precipitation, and the trypsin(ogen) thus obtained was purified by affinity chromatography on soybean trypsin inhibitor – Sepharose 4B. The purified trypsin migrated as a single zone during polyacrylamide gel electrophoresis and its identity as trypsin (EC 3,4.21.4) was established by its catalytic specificity for amide or ester bonds involving the carboxyl group of arginine, its sensitivity to serine protease inhibitors and soybean trypsin inhibitor, and its molecular weight of 23 500. With tosylarginine methyl ester (TAME) as substrate, the turnover number of the hydrolytic reaction was about three times greater for the cod trypsin than for bovine trypsin at 5 °C. The Michaelis–Menten constant (Km,app) for cod trypsin and TAME increased from 0.14 mM at 5 °C to 0.26 mM at 35 °C, while the Km,app for bovine trypsin – TAME was about 0.05 mM at all assay temperatures. The free energy of activation (ΔG*) for the hydrolysis of TAME was about 600 cal/mol (1 cal = 4.1868 J) lower for the cod trypsin than for bovine trypsin at 5 °C. The contribution of enthalpy of activation (ΔH*) and entropy of activation (ΔS*) to ΔG* differed considerably for the two enzymes. The "physiological efficiency" (Vmax/Km,app) of the two enzymes with TAME was similar at 5 °C, but was much greater for bovine trypsin than cod trypsin at warmer temperatures. With N-α-benzoylarginine-p-nitroanilide (BAPA) as substrate, the turnover number was about eight times greater for the cod trypsin at 25 °C. The Km,app for cod trypsin – BAPA increased from 1.67 mM at 25 °C to 1.84 mM at 35 °C, whereas the Km,app for bovine trypsin – BAPA decreased from 0.97 mM at 25 °C to 0.90 mM at 35 °C. The ΔG* for hydrolysis of BAPA was about 1800 cal/mol lower for cod trypsin than it was for bovine trypsin at 25 °C. Vmax/Km,app was three to four times greater for cod trypsin than for bovine trypsin at 25 and 35 °C. These results show that Greenland cod trypsin is a better catalyst than bovine trypsin at low temperatures and that catalysis by the fish trypsin is less responsive to temperature change than is catalysis by bovine trypsin.

scholarly journals Immunoreactivity of Lupine and Soybean Allergens in Foods as Affected by Thermal Processing

Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 254 ◽  
Author(s):  
Caterina Villa ◽  
Mónica B. M. V. Moura ◽  
Joana Costa ◽  
Isabel Mafra
Keyword(s):  
Trypsin Inhibitor ◽  
Thermal Processing ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Meat Products ◽  
Soybean Trypsin Inhibitor ◽  
Thermal Treatments ◽  
Food Matrix ◽  
Soybean Proteins ◽  
Sds Page

Lupine and soybean are important technological aids for the food industry. However, they are also capable of inducing severe allergic reactions in food-sensitized/allergic individuals. In this context, this work intended to study the combined effects of thermal processing and food matrix on the immunoreactivity of lupine and soybean proteins used as ingredients in bakery and meat products, respectively. For this purpose, the effects of baking, mild oven cooking, and autoclaving on the protein profiles were evaluated, using model mixtures simulating the production of lupine-containing breads and soybean-containing cooked hams/sausages, by native- and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and immunoblotting using specific antibodies. The results showed that lupine gamma-conglutin immunoreactivity was slightly decreased in wheat flour mixtures compared to rice, but it was more pronounced in baked products. In meat mixtures, substantial protein fragmentation was noted after autoclaving, with decreased immunoreactivity of soybean trypsin inhibitor. The analysis of 22 commercial products enabled the identification of lupine gamma-conglutin in four bakery samples and soybean trypsin-inhibitor in five sausages, and further differentiated autoclaved from other milder thermally treated products. Generally, the immunoreactivity of target proteins was reduced by all the tested thermal treatments, though at a higher extent after autoclaving, being slightly altered by the food matrix.

Cathepsin B and aminopeptidase in the posterior midgut of Phymata wolffii Stål (Hemiptera: Phymatidae)

1985 ◽  
Vol 63 (6) ◽  
pp. 1288-1291 ◽  
Author(s):  
Jon G. Houseman ◽  
P. E. Morrison ◽  
A. E. R. Downe
Keyword(s):  
Molecular Weight ◽  
Trypsin Inhibitor ◽  
Cathepsin B ◽  
Ethylenediaminetetraacetic Acid ◽  
Soybean Trypsin Inhibitor ◽  
Aminopeptidase Activity ◽  
Chloromethyl Ketone ◽  
Posterior Midgut ◽  
Hydrolysis Of

The posterior midgut of the phymatid Phymata wolffii Stål contains cathepsin B and aminopeptidase activity. Identification of cathepsin B was based on maximal hydrolysis of benzoyl-DL-arginine-2-naphthylamide and benzoyl-DL-arginine-p-nitroanilide at pH 5.8 and 5.5, respectively. Cathepsin B hydrolysis of the tested substrates was activated by thiol chemicals and ethylenediaminetetraacetic acid (EDTA) and inhibited by tosyl-L-lysine chloromethyl ketone, iodoacetamide, and soybean trypsin inhibitor. Aminopeptidase hydrolyzed leucine-p-nitroanilide maximally at pH 7.8 and hydrolysis of the substrate was activated by magnesium and inhibited by EDTA, dithiothreitol, glutathione, and cysteine. The molecular weight of cathepsin B was 40 000 and was greater than 150 000 for aminopeptidase.

scholarly journals Purification of an exo-β-D-glucanase from cell-free extracts of Candida utilis

1976 ◽  
Vol 159 (3) ◽  
pp. 555-562 ◽  
Author(s):  
V Notario ◽  
T G Villa ◽  
J R Villanueva
Keyword(s):  
Amino Acids ◽  
Enzyme Activity ◽  
Gel Electrophoresis ◽  
Candida Utilis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Polyacrylamide Gel ◽  
Acidic Amino Acids ◽  
Sepharose 4B ◽  
Hydrolysis Of

β-Glucanase present in cell-free extracts from Candida utilis was isolated and purified 562-fold by procedures that include adsorption on DEAE-Sephadex A-50 and filtration through columns of Sephadex G-50, G-100 and G-200, Bio-Gel P-10, and Concanavalin A-Sepharose 4B. The purified enzyme appeared homogeneous on polyacrylamide-gel electrophoresis and in ultracentrifugation studies (S20,w = 1.74S). The enzyme behaved as an acidic glycoprotein (pI4.1) with 68% carbohydrate and a high content of acidic amino acids. The mol.wt. was estimated to be 20000 from gel filtration and polyacrylamide-gel electrophoresis and 36000 from sedimentation experiments. Studies on the hydrolysis of different substrates showed that the enzyme is an unspecific β-glucanase able to break down both (1 leads to 3)-eta- and (1 leads to 6)-β-linkages by an exo-splitting mechanism. Glucono-δ-lactone, Zn2+ and Hg2+ inhibited the enzyme activity.

Low Molecular Weight Trypsin-Plasmin Inhibitors Isolated from Papain Treated Urinary Trypsin Inhibitor

1982 ◽  
Vol 47 (01) ◽  
pp. 014-018 ◽  
Author(s):  
H Sumi ◽  
N Toki ◽  
S Takasugi ◽  
S Maehara ◽  
M Maruyama ◽  
...  
Keyword(s):  
Trypsin Inhibitor ◽  
Gel Electrophoresis ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Chromatography ◽  
Urinary Trypsin Inhibitor ◽  
Plasmin Activity ◽  
Molecular Weights ◽  
Plasmin Inhibitors

SummaryPapain treatment of human urinary trypsin inhibitor (UTI67; mol. wt. 43,000 by SDS-polyacrylamide gel electrophoresis, specific activity 1,897 U/mg protein) produced four new protease inhibitors, which were highly purified by gel chromatography on Sephadex G-100 and isoelectric focusing. The purified inhibitors (UTI26, UTI9-I, UTI9-II, and UTI9-III) were shown to be homogeneous by polyacrylamide disc gel electrophoresis, and had apparent molecular weights of 26,000, 9,000, 9,000, and 9,800, respectively, by sodium dodecyl sulfate gel electrophoresis. During enzymatic degradation of UTI67, the amino acid compositions changed to more basic, and the isoelectric point increased from pH 2.0 (UTI67) to pHs 4.4, 5.2, 6.6, and 8.3 (UTI26, UTI9-I, UTI9-II, and UTI9-III), respectively. Both the parent and degraded inhibitors had anti-plasmin activity as well as antitrypsin and anti-chymotrypsin activities. Much higher anti-plasmin/anti-trypsin and anti-plasmin/anti-chymotrypsin activities were observed in the degraded inhibitors than in the parent UTI67. They competitively inhibited human plasmin with Ki values of 1.13 X 10-7 - 2.12 X 10-6 M (H-D-Val-Leu-Lys-pNA substrate). The reactions were very fast and the active site of the inhibitors to plasmin was thought to be different from that to trypsin or chymotrypsin.

Factor X Activation by washed human platelets

1979 ◽  
Author(s):  
E van Wijk ◽  
L Kahlé ◽  
J ten Cate
Keyword(s):  
Human Factors ◽  
Trypsin Inhibitor ◽  
Calcium Ions ◽  
Factor Xa ◽  
Human Platelets ◽  
Soybean Trypsin Inhibitor ◽  
Thrombin Inhibitor ◽  
Chromogenic Substrate ◽  
Factor X ◽  
Factor X Activation

In a system of washed human platelets, Ca2+and purified human factors X anc II, a sufficient amount of thrombin is generated in about 10 minutes to aggregate the platelets. This thrombin is formed through the activation of FX by the platelets. In a system with either FX or FII present, no aggregation occurs. In addition no aggregation is observed when hirudin, a specific thrombin inhibitor, or when soybean trypsin inhibitor, which inhibits factor Xa, are added to the mixture. The formation of factor Xa can be monitored indirectly through the generation of thrombin, in the presence of an excess of prothrombin, using a thrombin sensitive chromogenic substrate. When washed platelets are incubated with FX alone for 10 minutes, no aggregation occurs and after the addition of prothrombin aggregation starts within 6 minutes. These findings confirm that washed platelets possess a factor X activating property. The generation of FXa proceeds in the absence of added Ca2+, whereas in the presence of Ca2+factor Xa activity reaches a maximum in 3 minutes, whereafter the activity progressively decreases. This may be due to the binding of Xa to the platelets in the presence of calcium ions.

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