The His-Pro-Phe motif of angiotensinogen is a crucial determinant of the substrate specificity of renin.
The amino acid sequence His-Pro-Phe as N-terminal residues 6-8 of the natural renin substrate, angiotensinogen, is conserved among species. We investigated whether this His-Pro-Phe motif functions as the determinant of the substrate specificity of renin. Mutant angiotensinogens in which the Ile-His-Pro-Phe-His-Leu sequence at positions 5-10 of wild-type angiotensinogen was replaced by either His-Pro-Phe-His-Leu-Leu or Ala-Ile-His-Pro-Phe-His were cleaved by renin at the C-terminal side of residues 9 and 11, respectively, while wild-type angiotensinogen was cleaved at residue 10. A triple Ala substitution for the His-Pro-Phe motif of angiotensinogen prevented its cleavage by renin. In contrast, triple Ala substitution for residues 9-11, including the natural site of cleavage by renin, allowed cleavage between the two Ala residues at positions 10 and 11. Furthermore, the 33-residue C-terminal peptide of human megsin, which carries a naturally occurring His-Pro-Phe sequence, was cleaved by renin at the C-terminal side of the His-Pro-Phe-Leu-Phe sequence. These results indicate that the His-Pro-Phe motif of angiotensinogen is a crucial determinant of the substrate specificity of renin. By binding to a corresponding pocket on renin, the His-Pro-Phe motif may act as a molecular anchor to recruit the scissile peptide bond to a favorable site for catalysis.
Nakagawa
Tsutomu
T
Laboratory of Applied Biochemistry, Faculty of Applied Biological Science, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan. nakagawa@gifu-u.ac.jp
Akaki
Jyunji
J
Satou
Ryousuke
R
Takaya
Masatoshi
M
Iwata
Hideyuki
H
Katsurada
Akemi
A
Nishiuchi
Kazuhiro
K
Ohmura
Yoshihiro
Y
Suzuki
Fumiaki
F
Nakamura
Yukio
Y
D000595:Amino Acid Sequence; D000808:Angiotensinogen / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D000818:Animals; D001001:Anura; D002417:Cattle; D017124:Conserved Sequence; D004285:Dogs; D005399:Fishes; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D012083:Renin / Q000737:chemistry*; D016415:Sequence Alignment; D012756:Sheep; D013379:Substrate Specificity; D013879:Thioredoxins / Q000737:chemistry; D013997:Time Factors
D011993:Recombinant Fusion Proteins; D000808:Angiotensinogen; D013879:Thioredoxins; D012083:Renin