Solomon B, Moav N, Pines G, Katchalski-Katzir E
Mol Immunol. 1984 Jan;21(1):1-11. doi: 10.1016/0161-5890(84)90083-x.
Several mouse monoclonal antibodies to carboxypeptidase A (CPA) were prepared and purified, and their interaction with the enzyme was investigated. CPA is a well-characterized zinc-containing exopeptidase exhibiting peptidase as well as esterase activity. The antibodies obtained could be classified as follows: antibodies inhibiting mainly the peptidase activity of the enzyme, antibodies inhibiting mainly its esterase activity, antibodies affecting both activities, and antibodies which bind to the enzyme but have no marked effect on its catalytic properties. Binding constants of approximately 10(6) M-1 were obtained for most of the antibody-enzyme complexes tested. Additional information on the effect of the monoclonal antibodies on the active site of CPA was obtained by determining the change in the circular dichroism spectra of arsanilazotyrosine-248 carboxypeptidase A occurring as a result of the interaction of the enzyme with the antibodies studied. These findings suggest that CPA possesses at least three different specific antigenic sites, and that the active site of the enzyme for its peptidase activity differs from that for its esterase activity, though both sites seem to overlap to a considerable extent.
制备并纯化了几种针对羧肽酶A（CPA）的小鼠单克隆抗体，并研究了它们与该酶的相互作用。CPA是一种特征明确的含锌外肽酶，具有肽酶和酯酶活性。所获得的抗体可分类如下：主要抑制该酶肽酶活性的抗体、主要抑制其酯酶活性的抗体、影响两种活性的抗体以及与该酶结合但对其催化特性无明显影响的抗体。对于大多数测试的抗体-酶复合物，获得的结合常数约为10(6) M-1。通过测定由于所研究的抗体与酶相互作用而导致的对氨基苯砷酸酪氨酸-248羧肽酶A圆二色光谱的变化，获得了关于单克隆抗体对CPA活性位点影响的更多信息。这些发现表明，CPA至少具有三个不同的特异性抗原位点，并且该酶肽酶活性的活性位点与其酯酶活性的活性位点不同，尽管这两个位点似乎在很大程度上重叠。
