Pepsin from porcine gastric mucosa

Pepsin cleavage can be used to produce F(ab′)₂ fragments of antibodies. pepsin at www.sigma-aldrich.com/enzymeexplorer.

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 P7000 is provided as a powder and has been used to treat epithelial cells from a single feline mammary carcinoma.

The enzyme from Sigma has been used to simulate in vitro gastric digestion of cooked cod. It has been used to simulate in vitro gastric digestion of cocoa mass and supplemented dietary fiber. It has also been used to increase the fraction of extractable soluble collagen and to lower the immunogenicity of the resulting collagen from bovine dermal tissue.

Pepsin hydrolyzes peptide bonds, not amide or ester linkages. Pepsin cleaves peptides with an aromatic acid on either side of the peptide bond. Sulfur-containing amino acids increase susceptibility to hydrolysis when they are close to the peptide bond. Pepsin preferentially cleaves at the carboxyl side of phenylalanine and leucine and at the carboxyl side of glutamic acid residues. Cleaves Phe-Val, Gln-His, Glu-Ala, Ala-Leu, Leu-Tyr, Tyr-Leu, Gly-Phe, Phe-Phe and Phe-Tyr bonds in the β chain of insulin
Pepsin is the major proteolytic enzyme produced in the stomach. It digests proteins through the cleavage of interior peptide linkages..

Preferential cleavage: hydrophobic and aromatic residues in P1 and P1′ postitions. Cleaves Phe-Val, Gln-His, Glu-Ala, Ala-Leu, Leu-Tyr, Tyr-Leu, Gly-Phe, Phe-Phe and Phe-Tyr bonds in the β chain of insulin

The enzyme does not cleave at valine, alanine, or glycine linkages. Z-L-tyrosyl-L-phenylalanine, Z-L-glutamyl-L-tyrosine, and Z-L-methionyl-L-tyrosine may be used as substrates for pepsin digestion. Pepsin is inhibited by several phenylalanine-containing peptides.

Optimum pH is 2-4. Active in 4 M urea and 3 M guanidine HCl. Stable at 60 °C. Pepsin is irreversibly inactivated at pH 8.0 - 8.5.

One unit will produce a ΔA₂₈₀ of 0.001 per min at pH2.0 at 37 °C, measured as TCA-soluble products using hemoglobin as substrate. (Final volume = 16ml. Light path = 1cm.)

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