Molecular basis for the interaction of histamine with the histamine H2 receptor.
Molecular basis for the interaction of histamine with the histamine H2 receptor.
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DOI：
10.1016/s0021-9258(19)36764-x
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发表时间：
1992-10
期刊：
影响因子：
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通讯作者：
I. Gantz;J. Delvalle;L. Wang;T. Tashiro;G. Munzert;Y. Guo;Y. Konda;T. Yamada
中科院分区：
文献类型：
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作者：
I. Gantz;J. Delvalle;L. Wang;T. Tashiro;G. Munzert;Y. Guo;Y. Konda;T. Yamada
我们进行了这些研究，以表征组胺与H2受体相互作用的分子基础。组胺H2和β 2肾上腺素能受体结构中的关键同源性区域表明可能对组胺结合重要的特异性跨膜氨基酸。组胺受体的第三个跨膜天冬氨酸（Asp 98），被认为是作为与组胺的阳离子胺部分相互作用的抗衡阴离子，突变为Asn 98，突变的受体在Hepa细胞中表达。去除带负电荷的氨基酸废除了H2受体拮抗剂[甲基-3H]噻替丁和组胺刺激的细胞cAMP含量增加的结合。第五个跨膜天冬氨酸（Asp 186）突变为Ala 186或Asn 186本身或与另一个第五个跨膜氨基酸（Thr 190突变为Ala 190）结合导致[甲基-3H]噻替丁结合丧失，尽管维持了响应组胺的cAMP生成。只有一个Thr 190到Ala 190或Cys 190突变的组胺受体保留了结合[甲基-3H]噻替丁的能力，但结合的亲和力和效力都降低了。这些数据使我们提出了一个模型，其中Asp 98是必不可少的组胺结合和行动，Asp 186定义H2的选择性，和Thr 190是重要的，在建立组胺结合的动力学，但不是必不可少的H2的选择性。
We undertook these studies to characterize the molecular basis of the interaction of histamine with the H2 receptor. Key areas of homology in the structures of the histamine H2 and beta 2 adrenergic receptor suggested specific transmembrane amino acids that might be important for binding of histamine. A third transmembrane aspartic acid of the histamine receptor (Asp98), thought to serve as a counter anion that interacts with the cationic amine moiety of histamine, was mutated to Asn98, and the mutated receptor was expressed in Hepa cells. Removal of the negatively charged amino acid abolished both binding of the H2 receptor antagonist [methyl-3H]tiotidine and histamine stimulated increases in cellular cAMP content. Mutation of a fifth transmembrane aspartic acid (Asp186) to Ala186 or Asn186 by itself or in conjunction with mutation of another fifth transmembrane amino acid (Thr190 to Ala190) resulted in a loss of [methyl-3H] tiotidine binding, although the generation of cAMP in response to histamine was maintained. The histamine receptor with only a Thr190 to Ala190 or Cys190 mutation retained the ability to bind [methyl-3H]tiotidine, but both the affinity and efficacy of binding were reduced. These data lead us to propose a model for histamine binding in which Asp98 is essential for histamine binding and action, Asp186 defines H2 selectivity, and Thr190 is important in establishing the kinetics of histamine binding, but is not essential for H2 selectivity.