scholarly journals Linking inhibitor motions to proteolytic stability of sunflower trypsin inhibitor-1

RSC Advances ◽  
2019 ◽  
Vol 9 (24) ◽  
pp. 13776-13786
Author(s):  
Wanqing Wei ◽  
Jing Ma ◽  
Daiqian Xie ◽  
Yanzi Zhou
Keyword(s):  
Trypsin Inhibitor ◽  
Proteolytic Stability ◽  
Scissile Bond

Besides the non-bonded interactions, inhibitor motions especially rotation of the scissile bond also influence proteolytic stability.

scholarly journals An Unusual Helix-Turn-Helix Protease Inhibitory Motif in a Novel Trypsin Inhibitor from Seeds of Veronica (Veronica hederifolia L.)

2007 ◽  
Vol 282 (38) ◽  
pp. 27760-27768 ◽  
Author(s):  
Rebecca Conners ◽  
Alexander V. Konarev ◽  
Jane Forsyth ◽  
Alison Lovegrove ◽  
Justin Marsh ◽  
...  
Keyword(s):  
Protease Inhibitors ◽  
Trypsin Inhibitor ◽  
Disulfide Bonds ◽  
Serine Proteases ◽  
Enzyme Inhibitors ◽  
Noncovalent Complex ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Scissile Bond ◽  
Proteinaceous Inhibitor

The storage tissues of many plants contain protease inhibitors that are believed to play an important role in defending the plant from invasion by pests and pathogens. These proteinaceous inhibitor molecules belong to a number of structurally distinct families. We describe here the isolation, purification, initial inhibitory properties, and three-dimensional structure of a novel trypsin inhibitor from seeds of Veronica hederifolia (VhTI). The VhTI peptide inhibits trypsin with a submicromolar apparent Ki and is expected to be specific for trypsin-like serine proteases. VhTI differs dramatically in structure from all previously described families of trypsin inhibitors, consisting of a helix-turn-helix motif, with the two α helices tightly associated by two disulfide bonds. Unusually, the crystallized complex is in the form of a stabilized acyl-enzyme intermediate with the scissile bond of the VhTI inhibitor cleaved and the resulting N-terminal portion of the inhibitor remaining attached to the trypsin catalytic serine 195 by an ester bond. A synthetic, truncated version of the VhTI peptide has also been produced and co-crystallized with trypsin but, surprisingly, is seen to be uncleaved and consequently forms a noncovalent complex with trypsin. The VhTI peptide shows that effective enzyme inhibitors can be constructed from simple helical motifs and provides a new scaffold on which to base the design of novel serine protease inhibitors.

The role of the N34S mutation in the trypsin inhibitor gene SPINK1 in patients with chronic pancreatitis from Romania

2009 ◽  
Vol 47 (06) ◽  
Author(s):  
B Diaconu ◽  
A Schneider ◽  
R Pfützer ◽  
T Mocan ◽  
M Scăfaru ◽  
...  
Keyword(s):  
Chronic Pancreatitis ◽  
Trypsin Inhibitor ◽  
N34s Mutation ◽  
Inhibitor Gene

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.

THE EXCRETION OF TRYPSIN INHIBITOR IN URINE IN NORMAL PERSONS

1959 ◽  
Vol 30 (2) ◽  
pp. 285-295 ◽  
Author(s):  
Hans J. Faarvang
Keyword(s):  
Trypsin Inhibitor
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