Various properties of angiotensin-converting enzyme from the seal Phoca groenlandica
Sakharov, I.I.; Dukhanina, E.A.; Danilov, S.M.; Sakandelidze, O.G.
Biokhimiia 52(12): 1990-1993
1987
ISSN/ISBN: 0320-9725 PMID: 2833935 Document Number: 290926
It was found that the molecular mass of the angiotensin-converting enzyme from seal (Phoca groenlandica) lungs determined by electrophoresis in 7.5% PAAG in the presence of sodium dodecyl sulfate is 150 kD. The enzyme has a pH optimum with respect to hippuryl-L-histidyl-L-leucine at 7.3--7.5; KM is 1.2 mM. The enzyme is inhibited by the substrate to form a nonproductive ES2 complex with the dissociation constant (Ks') of 4.8 mM. The activation of the seal angiotensin-converting enzyme in the presence of NaCl was studied. The bradykinin-potentiating factor (SQ 20881) inhibits the seal enzyme with a high efficiency (IC50 = 2.5.10(-8) M). Monoclonal antibodies to the angiotensin-converting enzyme from human lungs do not interact with its seal lung counterpart, which points to the species specificity of the angiotensin-converting enzyme.