Two monoclonal antibody lines directed against subunit IV of cytochrome oxidase: a study of opposite effects.
Two monoclonal antibody lines directed against subunit IV of cytochrome oxidase: a study of opposite effects.
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两种针对细胞色素氧化酶 IV 亚基的单克隆抗体系：相反效应的研究。
DOI：
10.1016/0003-9861(88)90296-2
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发表时间：
1988
影响因子：
3.9
通讯作者：
Chan,SH
中科院分区：
文献类型：
--
作者：
Gai,WZ;Sun,SM;Ding,YZ;Freedman,JA;Chan,SH
分离到两株单克隆抗体，对牛心脏细胞色素氧化酶IV亚基氨基半部分具有特异性。这些细胞系具有不重叠的表位。两者都与膜氧化酶的基质面结合，两者都不与细胞质面结合。一条线（q4c4）刺激可溶性或膜性氧化酶的电子转移，而另一条线（QA4）通过两种氧化酶制剂抑制该活性。这些对电子转移活性的影响不因洗涤剂的加入或遗漏而改变。ATP抑制抗体与可溶性或膜性氧化酶的结合。在没有ATP的情况下，QA 4c4仅在细胞色素C氧化的高亲和力阶段（K M降低，V max增加）刺激电子转移，在低亲和力阶段（K M降低）引起轻微抑制。在ATP存在的情况下，QA 4c4消除了高亲和相，但没有改变ATP对低亲和相的影响。在没有ATP的情况下，QA4细胞系的抗体消除了低亲和力阶段，留下了类似ATP诱导的高亲和力阶段。在ATP存在的情况下，QA4消除了高亲和相，留下了与ATP单独存在时相似的低亲和相。这种行为与细胞色素c的两个催化位点和多个ATP影响位点的解剖是一致的。
Two monoclonal lines of antibodies were isolated with specificities against the amino half of Subunit IV of beef heart cytochrome oxidase. The lines had nonoverlapping epitopes. Both bound to the matrix face of membranous oxidase, neither bound to the cytoplasmic face. One line (QA 4 C 4) stimulated electron transfer in soluble or membranous oxidase, while the other (QA4) inhibited that activity by both oxidase preparations. These effects on electron transfer activity were not altered by the inclusion or omission of detergent. ATP depressed the binding of either antibody to either soluble or membranous oxidase. In the absence of ATP, QA 4 C 4 stimulated electron transfer only in the high affinity phase of cytochrome c oxidation (with decreased K M and increased V max), causing slight inhibition in the low affinity phase (with decreased K M). In the presence of ATP, QA 4 C 4 abolished the high affinity phase, but did not alter the ATP influence on the low affinity phase. In the absence of ATP, antibodies of line QA4 abolished the low affinity phase, leaving a high affinity phase similar to that induced by ATP. In the presence of ATP, QA4 abolished the high affinity phase, leaving a low affinity phase similar to that seen with ATP alone. This behavior is consistent with the dissection of two catalytic sites for cytochrome c and more than one ATP affector site.