[来自格陵兰海豹的血管紧张素转换酶的各种特性]

[Various properties of angiotensin-converting enzyme from the seal Phoca groenlandica].

作者信息

Sakharov Iu I, Dukhanina E A, Danilov S M, Sakandelidze O G

出版信息

Biokhimiia. 1987 Dec;52(12):1990-3.

Abstract

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.

摘要

研究发现，在十二烷基硫酸钠存在的情况下，通过在7.5%聚丙烯酰胺凝胶中电泳测定，格陵兰海豹（Phoca groenlandica）肺中的血管紧张素转换酶分子量为150 kD。该酶以马尿酰-L-组氨酰-L-亮氨酸为底物时，最适pH为7.3 - 7.5；米氏常数（KM）为1.2 mM。该酶被底物抑制，形成非生产性的ES2复合物，解离常数（Ks'）为4.8 mM。研究了在氯化钠存在下海豹血管紧张素转换酶的激活情况。缓激肽增强因子（SQ 20881）对海豹酶具有高效抑制作用（半数抑制浓度IC50 = 2.5×10⁻⁸ M）。针对人肺血管紧张素转换酶的单克隆抗体不与其海豹肺对应物相互作用，这表明血管紧张素转换酶具有物种特异性。