Trypsin Inhibitor Soybean - reagent grade, high purity , CAS No.9035-81-8

Item Number

T113170

• Synonyms: SBTI
• Specifications & Purity: Animal Free, From Soybean
• Biochemical and Physiological Mechanisms: 该抑制剂可作用于胰蛋白酶，而对胰凝乳蛋白酶和纤溶酶的作用较弱。 它还可抑制机制与胰蛋白酶、血浆型激肽释放酶和凝血因子X相似的蛋白酶。 胰蛋白酶抑制剂对金属蛋白酶、基于组织型激肽释放酶、酸性蛋白酶或硫代蛋白酶不起作用。 该抑制剂与蛋白酶活性位点形成化学计量比1:1的复合物，然后在裂解抑制剂上的单个精氨酸-异亮氨酸键，从而发挥作用。 抑制作用可逆且呈pH依赖性。
• Storage Temp: Store at 2-8°C
• Shipped In: Wet ice
• Grade: Animal Free

Product Description

Molecular weight: 21,500 ± 800 (Wu and Scheraga 1972a).

Optimum pH: 7.0.

Composition: The Kunitz soybean inhibitor consists of a single polypeptide chain crosslinked by two disulfide bridges (Steiner 1965). Structural studies of the inhibitor and active site have been reported, Ellis et al. (1975), Woodward and Ellis (1975), Koide et al. (1974), Koide and Ikenaka (1973), Bidlingmeyer et al. (1972), Ikenaka et al. (1971), Papaioannou and Liener (1970), Hixson and Laskowski (1970), Kato and Tominager (1970), and Wu and Scherage (1962). Donovan and Beardslee (1975) have reported on the thermal denaturation of inhibitor complexes.

Isoelectric point: 4.5 (Kunitz 1947).

Specificity: Soybean inhibitor inhibits trypsin mole-for-mole and to a lesser extent chymotrypsin. (Bidlingmeyer et al. 1972). Lanchantin et al. (1969) report soybean inhibitor to form a one-to-one complex with beef or human thrombin thus blocking its specific proteolytic capacity to activate prothrombin. Nanninga and Guest (1964) report plasmin to be inhibited. STI has been reported to inhibit leukocytic proteases. (Lieberman and Gawad 1971), but not the esterolytic, proteolytic or elastolytic activities of porcine elastase (Gertler and Feinstein 1971).

Soybean Trypsin Inhibitor (Kunitz)：

Soybean trypsin inhibitor (SBTI) first crystallized by Kunitz (1945) is one of several such inhibitors found in soybeans. (Fratalli 1969; Millar et al. 1969; Fratalli and Steiner 1968; Birk et al. 1967). The best known preparation is that of Kunitz. Steiner and Fratalli (1969) have reviewed the Kunitz and Bowman-Birk inhibitors. A protein (or polypeptide) proteinase inhibitor probably has peptide bonds compatible with the protease reactive site. Finkenstadt and Laskowski (1965 and 1967) and Ozawa and Laskowski (1966) indicate that a single Arg-Ile bond is cleaved by trypsin; a covalent bimolecular complex of inhibitor and trypsin results. On dissociation either virginal or modified inhibitor appears; see Hixson and Laskowski (1970a), Isheda et al. (1970) and Niekamp et al. (1969).

Enzyme activity definition：

The activity of the inhibitors is expressed as the amount of twice crystallized trypsin (Aladdin Item: T128774) inhibited per milligram of inhibitor. 1mg trypsin ≥180 TAME units, 10,350 BAEE units, 3,450 USP/NF units.