Roles of His9 (P2 subsite) and His13 (P3' subsite) in angiotensinogen for catalytic reaction of renin.
Roles of His9 (P2) and His13 (P3') of angiotensinogen for the catalytic reaction of renin were investigated using purified recombinant ovine angiotensinogen and its mutants H9Q and H13Q. The pH depended reaction of human renin with angiotensinogens of wild-type, H9Q and H13Q showed peaks at pH 6.5 and 8.5, but the altitude of each peak was different. The Vmax of the reaction between H9Q and H13Q with human renin was decreased by about 50 and 70%, respectively, in comparison to wild-type angiotensinogen, at pH 6.5. At pH 8.5, the Vmax of H9Q and H13Q was 50 and 100% of that of wild-type, respectively. At pH 6.5, it was revealed that the catalytic efficiency of renin (Vmax/Km) reduced to 20 and 60% after mutation of angiotensinogen at His9 and His13 with Gln, respectively. At pH 8.5, the catalytic efficiency decreased to 10 and 70% after these mutations, respectively. These findings, therefore, indicate that histidine residues at both P2 and P3' positions probably associate with the renin catalytic reaction for angiotensin I generation.
Nabi
A H M Nurun
AH
United Graduate School of Agricultural Science, Faculty of Applied Biological Science, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
Uddin
Mohammad Nasir
MN
Nakagawa
Tsutomu
T
Orihashi
Takenori
T
Ebihara
Akio
A
Iwasawa
Atsushi
A
Nakamura
Yukio
Y
Suzuki
Fumiaki
F
D000595:Amino Acid Sequence; D000803:Angiotensin I / Q000096:biosynthesis; D000808:Angiotensinogen / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D016466:CHO Cells; D002384:Catalysis; D006224:Cricetinae; D006639:Histidine / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D017434:Protein Structure, Tertiary; D012083:Renin / Q000378:metabolism*; D016415:Sequence Alignment; D012756:Sheep
D000808:Angiotensinogen; D006639:Histidine; D000803:Angiotensin I; D012083:Renin