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Metabolism of angiotensins by head membranes of the leech Theromyzon tessulatum
Author(s) -
Laurent Virginie,
Salzet Michel
Publication year - 1996
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(96)00293-1
Subject(s) - phosphoramidon , renin–angiotensin system , angiotensin iii , neprilysin , chemistry , aminopeptidase , angiotensin converting enzyme , biochemistry , enzyme , membrane , angiotensin ii , exopeptidase , enkephalin , leech , biology , endocrinology , angiotensin receptor , amino acid , opioid , receptor , leucine , blood pressure , world wide web , computer science
Angiotensins (angiotensin I, angiotensin II, angiotensin II‐amide) have been isolated in leeches and such peptides are involved in diuresis in these animals. To explore possible inactivation mechanisms of these peptides, angiotensins were incubated with head membranes of the leech T. tessulatum . Membranes derived from head parts of this leech are very rich in peptidases. They contain endopeptidase‐24.11‐like enzyme (NEP‐like) associated with a battery of exopeptidase. The way that angiotensins are degraded by the combined attack of these membrane peptidases has been investigated. The contribution of individual peptidases was assessed by adding inhibitors (phosphoramidon, captopril and amastatin) to the membrane fractions, when they were incubated with the peptides. In the case of angiotensin I, the primary attack was performed by a combined action of the NEP‐like and the ACE‐like enzymes, followed by aminopeptidase attacks. Angiotensin II and III were hydrolyzed by NEP‐like enzyme at the same Tyr‐Ile bond, whereas the N‐terminal arginine residue of angiotensin III was removed by an arginyl aminopeptidase. These results show that angiotensins are efficiently degraded by membranes and that NEP‐like enzyme plays a key role in this process.