title: Primary structure, unique enzymatic properties, and molecular evolution of pepsinogen B and pepsin B.
abstract: Purification of pepsinogen B from dog stomach was achieved. Activation of pepsinogen B to pepsin B is likely to proceed through a one-step pathway although the rate is very slow. Pepsin B hydrolyzes various peptides including beta-endorphin, insulin B chain, dynorphin A, and neurokinin A, with high specificity for the cleavage of the Phe-X bonds. The stability of pepsin B in alkaline pH is noteworthy, presumably due to its less acidic character. The complete primary structure of pepsinogen B was clarified for the first time through the molecular cloning of the respective cDNA. Molecular evolutional analyses show that pepsinogen B is not included in other known pepsinogen groups and constitutes an independent cluster in the consensus tree. Pepsinogen B might be a sister group of pepsinogen C and the divergence of these two zymogens seems to be the latest event of pepsinogen evolution.
authors.affiliation: Center for Human Evolution Modeling Research, Primate Research Institute, Kyoto University, Inuyama 484-8506, Japan. narita@pri.kyoto-u.ac.jp
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Narita
authors.forename: Sen-ichi
authors.initials: S
authors.lastname: Oda
authors.forename: Akihiko
authors.initials: A
authors.lastname: Moriyama
authors.forename: Takashi
authors.initials: T
authors.lastname: Kageyama
mesh_terms: D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004285:Dogs; D004789:Enzyme Activation / Q000502:physiology; D004795:Enzyme Stability / Q000502:physiology; D019143:Evolution, Molecular; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008969:Molecular Sequence Data; D010434:Pepsin A / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification; D010435:Pepsinogens / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid; D013270:Stomach / Q000737:chemistry / Q000201:enzymology; D013379:Substrate Specificity / Q000502:physiology
chemical_list: D010435:Pepsinogens; D010434:Pepsin A; C095924:pepsin B