title: Refined 1.8 A resolution crystal structure of the porcine epsilon-trypsin.
abstract: Porcine epsilon-trypsin is a three-chain inactivated trypsin from the limited autolysis of porcine beta-trypsin. It is cleaved at positions Lys60-Ser61 and Lys145-Ser146. The crystal structure has been determined by using the molecular replacement method, and refined at 1.8 A resolution. The R-value of final model is 0.184. Comparison with the electron density map of porcine beta-trypsin (PTRY) in complex (BBIT), and with that of native bovine beta-trypsin (HTNA), revealed no obvious changes except at the autolysis positions, and no changes at the active center were observed. The autolysis at positions Lys60-Ser61 and Lys145-Ser146 does not affect the conformation of His-57 in the active center and therefore cannot explain for a loss in porcine epsilon-trypsin activity.
authors.affiliation: Department of Chemistry, Peking University, Beijing, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Huang
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.forename: S
authors.initials: S
authors.lastname: Liu
authors.forename: Y
authors.initials: Y
authors.lastname: Tang
mesh_terms: D000818:Animals; D002417:Cattle; D011487:Protein Conformation; D013552:Swine; D014357:Trypsin / Q000737:chemistry*
chemical_list: D014357:Trypsin