| Abstract: | Biochemical and immunological properties of two kinds of pepsinogens isolated from the gastric mucosal extracts of adult Wistar rats were studied. Their activated enzymes were prepared from the zymogens using a DEAE-Sepharose CL-6B column. The isoelectric points of pepsinogens I and II were estimated to be 3.90 and 3.75, respectively, by isoelectric focusing, and those of pepsins I and II to be 3.60 and 3.45, respectively. Amino acid compositions of the two pepsinogens or pepsins were strikingly similar to each other and neither pepsinogen I nor II contained organic phosphate. The biochemical properties of rat preparations compared with porcine pepsinogens A and C and pepsins A [EC 3.4.23.1] and C [EC 3.4.23.3] showed that rat pepsinogens and pepsins resembled porcine pepsinogen C and pepsin C, respectively. Pepsinogens I and II were demonstrated to share a similar immunogenic molecular structure by double diffusion analysis and Laurell immunoelectrophoresis. Rabbit antipepsinogen I serum cross-reacted with the mouse preparation but did not with the rabbit and porcine preparations. The possibility of the genetically controlled occurrence of pepsinogens I and II in the rat is discussed. |
