PURIFICATION AND SOME PROPERTIES OF RECOMBINANT SHEEP ANGIOTENSINOGENEXPRESSED IN CHINESE-HAMSTER OVARY CELLS

We established an expression system for large amount of recombinant sh eep angiotensinogen gen (sAngn) in Chinese hamster ovary cells. The re combinant sAngn (21.6 mg) was purified by a single column chromatograp hy to a homogeneous level on sodium dodecyl sulphate-polyacrylamide ge l electrophoresis from 2.71 of conditioned medium. Human renin cleaved only a Leu(10)-Leu(11) bond in sAngn, although Leu(11)-Val(12) was an other candidate for scissile peptide bond. The K-m and k(cat) values f or the reaction of human renin with sAngn were 0.21 mu M and 150 min(- 1), respectively. Recombinant rat renin could also react with the sAng n. The K-m and k(cat) for the reaction were 0.84 mu g and 78 min(-1), respectively. Purified sAngn was stable at temperature up to 50 degree s C, but rapidly inactivated at that higher than 55 degrees C.