On the interaction of inhibitor and proteases Evidence for the formation of a covalent crosslinkage and non-covalent weak bondings between the inhibitor and proteases

Monoclonal antibodies produced against protein‐type inhibitors from pea or soybean were used for investigations of the chemical and antigenic properties of trypsin and chymotrypsin inhibitors from pea. Cross‐reactivity studies revealed only the existence of Bowman‐Birk‐type inhibitors in pea. The inhibitors could be divided into at least two groups of iso‐inhibitors based on their characteristics in binding to different monoclonal antibodies produced against pea trypsin inhibitors or Bowman‐Birk inhibitor from soybean. The inhibitor contents in a series of pea extracts were measured in an ELISA‐based system using the different antibodies. Comparison with the inhibitor activity measured by traditional enzymatic analysis performed as microassay showed that only the inhibitor content of one of the two inhibitor groups correlated strongly with the trypsin inhibitor activity. The immunoassay was also shown to be suitable for measurement of inhibitor content after heat treatment as the results suggested that the two inhibitor groups contained equally heat resistant inhibitors.

Trypsin inhibitor

Proteinase inhibitor

10.1080/09540109409354814

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Citations (5)

The Protease Inhibitors of Seeds

Advances in cellular and molecular biology of plants (1997)

Karl A. Wilson

Trypsin inhibitor

Protease inhibitor (pharmacology)

Cysteine protease

Serine Proteinase Inhibitors

Serpin

MASP1

10.1007/978-94-015-8909-3_9

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Citations (9)

Protein and Amino Acid Composition of Domestic Potato Cultivars

Journal of the Korean Society of Food Science and Nutrition (2008)

권오윤 김미연 손찬욱 류희문 김형진

국내에서 생산된 감자 중 세풍, 남서, 수미, 조풍 및 대서의 5가지 품종에 대하여 단백질 profile 및 아미노산 조성을 분석하였다. 총 질소함량은 1.27～1.64%이었으며, 남서가 높았고 수미가 낮게 나타났다. 아미노산 조성은 품종 간에 유의적인 차이가 있었다. 한편, 주요 감자 단백질은 papatin(40 kDa), trypsin inhibitor(20 kDa) 및 protease inhibitor(15 kDa)이었으며, 이들의 함량은 각각 22.16～25.81%, 25.22～20.91% 및 14.12～25.23%이었다. Papatin 함량은 조풍, 세풍, 수미감자가 높은 함량을 보인 반면, trypsin inhibitor는 조풍감자가 5.22%로 가장 낮은 함량을 보였다. Protease inhibitors인 20 kDa와 15 kDa를 합한 값은 24.7～35.0%이었으며, 세풍이 가장 적었고 조풍에 가장 많이 함유되어 있었다.

Trypsin inhibitor

Protease inhibitor (pharmacology)

Amino Acid Analysis

10.3746/jkfn.2008.37.1.117

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Citations (7)

The Inter-α-Trypsin Inhibitor as Precursor of the Acid-Stable Proteinase Inhibitors in Human Serum and Urine

Hoppe-Seyler´s Zeitschrift für physiologische Chemie (1976)

Karl HOCHSTRASSER G Bretzel H. Feuth Wolfgang Hilla Kathrin Lempart

A small amount of antitryptic activity is detectable in the supernatant of deproteinized human serum. Preincubation of serum with trypsin causes an increase in acid-stable antitryptic activity. This rise in activity depends on the inter alpha-trypsin inhibitor concentration. The native inhibitor present in normal sera, and in higher concentrations in sera of patients with nephropathies, and the trypsin-liberated inhibitor show immunological cross reaction with antibodies to the serum inter-alpha-trypsin inhibitor. The two inhibitors differ in molecular weight and electrophoretic mobility. The physiological inhibitor (I-34), with a molecular weight of 34 000 and a high carbohydrate content, can be transformed by trypsin into an inhibitor (I-17) with a molecular weight of 17 000. This inhibitor is identical with the inhibitors liberated by trypsin from serum or from purified inter-alpha-trypsin inhibitor. The acid-stable inhibitor from urine is identical with the physiological serum inhibitor. Analogously, this inhibitor is transformed by trypsin into the inhibitor with a molecular weight of 17 000. We conclude that the inter-alpha-trypsin inhibitor is the precursor of both the physiological and the trypsin-liberated inhibitor. By a mechanism as yet unknown, but most likely a limited proteolysis, the secreted inhibitor is liberated from the high molecular weight precursor. In contrast to the monospecific trypsin-inhibiting precursor, the physiological and artificially liberated inhibitors are trypsin/chymotrypsin/plasmin inhibitors.

Trypsin inhibitor

Proteolysis

Proteinase inhibitor

Inhibitor protein

10.1515/bchm2.1976.357.1.153

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Citations (108)

Inhibition of radiation-induced transformation of C3H/10T1/2 cells by carboxypeptidase inhibitor 1 and inhibitor II from potatoes

Carcinogenesis (1989)

Paul C. Billings Anne R. Morrow Clarence A. Ryan Ronald C. Kennedy

In the current study, the ability of four protease inhibitors to suppress radiation-induced transformation of C3H/10T1/2 cells was investigated. The inhibitors tested included: (i) aprotinin (a serine protease inhibitor), (ii) N-acetyl-L-tyrosine ethyl ester (a chymotrypsin substrate and competitive inhibitor of protein degradation), (iii) carboxypeptidase inhibitor (a metallo-exopeptidase inhibitor) and (iv) Inhibitor II (a chymotrypsin/trypsin inhibitor). While none of the inhibitors were toxic to the cells at the concentrations employed, only carboxypeptidase inhibitor and inhibitor II are internalized radiation-induced transformation in a statistically significant manner. Utilizing fluorescent labeled inhibitors, we found that carboxypeptidase inhibitors and Inhibitor II are internalized by the cells. Fluorescent-labeled inhibitor could be observed in the cells within 15 min of incubation and is present in distinct intercellular vacuoles within 1 h. These results indicate that carboxypeptidase inhibitor and Inhibitor II are internalized by C3H/10T1/2 cells and thus would be able to inhibit intracellular proteases (or other enzymes) involved in the conversion of a cell to the malignant state.

Protease inhibitor (pharmacology)

Carboxypeptidase A

Trypsin inhibitor

Aprotinin

Serine Proteinase Inhibitors

10.1093/carcin/10.4.687

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Citations (30)

A Detecting Method for Protease Inhibitors by Gelatin-Tricine-SDS-PAGE

Lishizhen Medicine and Materia Medica Research (2008)

Liping Li

Objective To establish an detecting method for protease inhibitors,especially for low-molecular-weight inhibitors.Methods Inhibitor samples were separated on a gelatin-SDS-PAGE in a Tris-Tricine buffer system.After electrophoresis,the gel was incubated with the target proteases to hydrolyze the background gelatin.The inhibitor bands,which were undigested by the target proteases,were stained.Results Low-molecular-weight inhibitor(pepstatin A) and larger inhibitor(soybean Bowman-Birk inhibitor) were demonstrated by this method and showed clear blue inhibitor bands in the white background.By this method,a trypsin inhibitor was detected from the seeds of Albizzia kalkora(Roxb.) Prain.Conclusion This method not only fit for inhibitors with different molecular mass,but fits for inhibitors with various species.Moreover,the trypsin inhibitor found in Albizzia kalkora is important for further research and overall exploration.

Tricine

Gelatin

Trypsin inhibitor

Protease inhibitor (pharmacology)

Bromelain

Molecular mass

Source

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Citations (0)

[58] Trypsin and chymotrypsin inhibitors from soybeans

Methods in enzymology on CD-ROM/Methods in enzymology (1976)

Yehudith Birk