性质
折叠
产品描述
Analysis Note
Protein determined by E1%/280
最佳 pH 值为 2-4。在 4M 脲和 3M 盐酸胍中具有活性。在 60°C 下能稳定存在。在 pH 8.0-8.5 下可对胃蛋白酶进行不可逆地灭活。
Application
用于产生抗体的 F(ab′)2 片段。
Pepsin from Sigma has been used along with other enzymes for the determination of enzyme-resistant starch (RS) in bread.[3] It has also been used to simulate in vitro gastrointestinal digestion of pea or whey protein isolates.[1]
Pepsin is a peptidase used to digest proteins and is commonly used in the preparation of Fab fragments from antibodies. Pepsin, from porcine gastric mucosa, has been used to hydrolyze dry cervical samples in mice. Product P6887 is provided as a lyophilized powder and has been used to digest protein during dietary fiber analysis[2].
Biochem/physiol Actions
优先裂解:P1 和 P1′ 位的疏水性和芳族残基。降解胰岛素 β 链中的 Phe-Val、Gln-His、Glu-Ala、Ala-Leu、Leu-Tyr、Tyr-Leu、Gly-Phe、Phe-Phe 和 Phe-Tyr 键
Unlike many other peptidases, pepsin hydrolyzes only peptide bonds, not amide or ester linkages. The cleavage specificity includes peptides with an aromatic acid on either side of the peptide bond, especially if the other residue is also an aromatic or a dicarboxylic amino acid. Increased susceptibility to hydrolysis occurs if there is a sulfur-containing amino acid close to the peptide bond, which has an aromatic amino acid. Pepsin will also preferentially cleave at the carboxyl side of phenylalanine and leucine, and to a lesser extent at the carboxyl side of glutamic acid residues. It does not cleave at valine, alanine, or glycine linkages.[4] Z-L-tyrosyl-L-phenylalanine, Z-L-glutamyl-L-tyrosine, or Z-L-methionyl-L-tyrosine may be used as substrates for pepsin digestion.[4][5] Pepsin is inhibited by several phenylalanine-containing peptides.[6]
Other Notes
View more information on pepsin at www.sigma-aldrich.com/enzymeexplorer.
包装
1, 5, 10 g in glass bottle
250 mg in glass bottle
Unit Definition
One unit will produce a ΔA280 of 0.001 per min at pH 2.0 at 37°C, measured as TCA-soluble products using hemoglobin as substrate. (Final volume = 16 ml. Light path = 1 cm.)