Corn Trypsin Inhibitor

In this study, we found that the inhibition of fungal growth in potato dextrose broth (PDB) medium by the 14-kDa corn trypsin inhibitor (TI) protein, previously found to be associated with host resistance to aflatoxin production and active against various fungi, was relieved when exogenous α-amylase was added along with TI. No inhibitory effect of TI on fungal growth was observed when Aspergillus flavus was grown on a medium containing either 5% glucose or 1% gelatin as a carbon source. Further investigation found that TI not only inhibited fungal production of extracellular α-amylase when A. flavus was grown in PDB medium containing TI at 100 μg ml-1 but also reduced the enzymatic activity of A. flavus α-amylase by 27%. At a higher concentration, however, TI stimulated the production of α-amylase. The effect of TI on the production of amyloglucosidase, another enzyme involved in starch metabolism by the fungus, was quite different. It stimulated the production of this enzyme during the first 10 h at all concentrations studied. These studies suggest that the resistance of certain corn genotypes to A. flavus infection may be partially due to the ability of TI to reduce the production of extracellular fungal α-amylase and its activity, thereby limiting the availability of simple sugars for fungal growth. However, further investigation of the relationship between TI levels and fungal α-amylase expression in vivo is needed.

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Novel Thermostable Inhibitor of Contact Activation Tica Effectively Blocks Contact Activation in Low Tissue Factor Thrombin Generation

Blood ◽

10.1182/blood-2019-130875 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 1146-1146

Author(s):

Tom Van De Berg ◽

Dennis P.L. Suylen ◽

M.G.L. Christella D. Thomassen ◽

Rene van Oerle ◽

Henri M.H. Spronk ◽

...

Keyword(s):

Shelf Life ◽

Tissue Factor ◽

Trypsin Inhibitor ◽

Thrombin Generation ◽

Conflicts Of Interest ◽

Blood Collection ◽

Contact Activation ◽

Current Standard ◽

Blood Drawing ◽

Corn Trypsin Inhibitor

Background: Thrombin generation and other clotting assays suffer from a wide variation of pre-analytical variables. One of those pre-analytical variables is contact activation through blood withdrawal methods, different syringes, differences in blood coagulation tubes, blood transport and sample handling. It has been shown that the addition of contact activation inhibitors in low tissue factor activated thrombin generation leads to a correction of the, in these circumstances significant, increase in thrombin generation due to contact activation. We compare the novel 'thermostable inhibitor of contact activation' (TICA) to the current standard 'corn trypsin inhibitor' (CTI). Aim: Comparing the effectiveness of novel contact activation inhibitor TICA to the current standard CTI in low tissue factor-induced thrombin generation and recalcification in sodium citrate anticoagulated platelet poor plasma (PPP) and platelet rich plasma (PRP). Methods: We compared TICA, Corn trypsin inhibitor and plasma without contact activation inhibitors in low tissue factor PPP thrombin generation and in PRP recalcification thrombin generation, the latter the most sensitive condition for contact activation. In addition, we compared low tissue factor activated thrombin generation in plasma from severe hemophilia A patients with and without TICA during and after blood drawing. Thermostability - as a measure of shelf life - was measured and compared to CTI. Results: TICA is able to fully block contact activation in PRP recalcification experiments and is comparable to CTI in doing so. TICA significantly lowers low tissue factor induced thrombin generation by blocking contact activation. Pre-loading vacuum blood collection tubes with contact activation inhibitors is superior in inhibiting contact activation compared to addition of the inhibitor during the thrombin generation assay itself. TICA did not alter coagulation activity when added to FXIIa deficient plasma in thrombin generation. In contrast to CTI TICA is heat stable which will be of benefit to shelf life of pre-loaded blood drawing tubes. Conclusion: TICA is able to fully block contact activation and has several advantages over CTI. Disclosures No relevant conflicts of interest to declare.

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An examination of the inhibitory properties of corn trypsin inhibitor on Hageman factor

Biochemical Society Transactions ◽

10.1042/bst028a362b ◽

2000 ◽

Vol 28 (5) ◽

pp. A362-A362

Author(s):

K. J. Real ◽

B. F. Masterson

Keyword(s):

Trypsin Inhibitor ◽

Hageman Factor ◽

Corn Trypsin Inhibitor

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Assembly of High Molecular Weight Kininogen and Activation of Prekallikrein on Cell Matrix

Thrombosis and Haemostasis ◽

10.1055/s-0037-1616141 ◽

2001 ◽

Vol 86 (09) ◽

pp. 840-847 ◽

Cited By ~ 28

Author(s):

Z. Shariat-Madar ◽

F. Mahdi ◽

C. A. M. Sampaio ◽

A. H. Schmaier ◽

G. Motta

Keyword(s):

Molecular Weight ◽

Endothelial Cells ◽

High Molecular Weight ◽

Trypsin Inhibitor ◽

Umbilical Vein ◽

Sodium Dodecyl ◽

Factor Xii ◽

High Molecular Weight Kininogen ◽

Urokinase Plasminogen Activator Receptor ◽

Corn Trypsin Inhibitor

SummaryInvestigations determined if extracellular matrix of endothelial cells (EC) is a platform for HK assembly and PK activation. In buffers containing bovine serum albumin, biotin-HK binding to ECV304 cells or their matrix requires ≥ 50 µM added Zn 2+. Ortho-phenanthroline or a HK domain 5 peptide blocks HK binding. Binding to umbilical vein EC or matrix, but not ECV304 cells or matrix, is mediated by cytokeratin 1. Biotin-HK binds to ECV304 cells or matrix with a Kd of 15.8 or 9.0 nM and a Bmax of 2.6 107 or 2.4 107 sites/cell, respectively. PK activation on ECV304 cells or matrix is blocked by antipain or SBTI and corn trypsin inhibitor partially inhibits kallikrein formation. PK activation occurs on ECV304 cells or matrix prepared without serum or in human factor XII deficient serum, indicating that the PK activator is not factor XIIa. EC matrix promotes plasminogen activation after the assembly of HK, PK and pro-urokinase. These studies indicate that matrix of various EC has the ability to assemble HK allowing for PK activation and subsequent activities.Abbreviations: EC: endothelial cells, FXII: factor XII, HK: high molecular weight kininogen, HKa: bradykinin-free HK, PK: plasma prekallikrein, Pro-UK: pro-urokinase, uPAR: urokinase plasminogen activator receptor, tcuPA: twochain urokinase, CK1: cytokeratin 1, SBTI: soybean trypsin inhibitor, HUVEC: human umbilical vein endothelial cell, SDS-PAGE: sodium dodecyl sulfatepolyacrylamide gel electrophoresis, CTI: corn trypsin inhibitor, p-APMSF: p-amidinophenylmethylsulfonylfluoride, EBSS: Earle’s Balanced Salt Solution

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