A renin-like enzyme in the leech Theromyzon tessulatum

MOLECULAR AND CELLULAR ENDOCRINOLOGY

卷:131

Article

Salzet, M ; Stefano, G

关键词: angiotensins;    leech;    microsequence;    phylogeny;    renin-angiotensin system;    renin-like enzyme;   

DOI  :  10.1016/S0303-7207(97)04060-4

来源: Elsevier

【 摘 要 】

We report on the biochemical isolation and characterization of a 32 kDa aspartyl protease from the leech Theromyzon tessulatum. Following a three step purification (gel permeation chromatography, pepstatin A-sepharose affinity column separation followed by reversed-phase HPLC) a renin-like enzyme was purified to homogeneity, The first 124 amino acid residues of the N-terminal part of the purified S-pyridylethylated leech renin exhibits a 26.5-35.5% sequence identity with that of mammals. The 20-81 region of leech renin exhibits a 80% sequence homology with the 175-232 region in mammals. This highly conserved region, which is also found in all aspartic proteases, possesses the aspartyl catalytic residue (D(11)TGSS). Leech renin hydrolyses at neutral pH and at 37 degrees C the Leu(10)-Leu(11) bond of synthetic porcine angiotensinogen tetradecapeptide yielding the angiotensin I and the Leu(11)-Val(12)-Tyr(13)-Ser(14) peptides, with a specific activity of 115 mu g AI/min/mg (K-m, 22 mu M; K-cat, 2.7). This hydrolysis is inhibited by pepstatin A (IC50: 4.6 mu M) Moreover, this enzyme is found on a multiple hormone precursor of 19 kDa which exhibits a specific activity of 850 pmol AI/min/mg of renin. This is the first biochemical characterization of a renin-like enzyme in invertebrates and non-mammalian vertebrates. (C) 1997 Elsevier Science Ireland Ltd.

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