Sadeghi H, Lumanglas A L, Baumbach W R, Wang B S
Agricultural Research Division, American Cyanamid Company, Princeton, New Jersey 08543-0400.
J Endocrinol. 1993 Dec;139(3):495-501. doi: 10.1677/joe.0.1390495.
The properties of four independent lines of monoclonal antibodies (MAbs) specific to rat GH-binding protein (GHBP) were examined. Three MAbs, designated GHR-12, GHR-13 and GHR-16, were raised against the entire GHBP molecule. The fourth MAb, designated as GHBP4.3, was raised against the 17 amino acid residues at the C-terminal end of rat GHBP. The interaction of these antibodies with GHBP and their effect on GH binding to GHBP were analysed by conventional competition binding assays and surface plasmon resonance, i.e. with a Biospecific Interaction Analysis (BIAcore) instrument. The binding affinity of these MAbs to GHBP ranged from 29 nmol/l to 30.9 pmol/l. The pair-wise antibody binding to GHBP on BIAcore suggested that GHR-13 and GHR-16 recognized different antigenic determinants while part of the GHR-12 epitope might be shared with the other antibodies. The antibodies inhibited the interaction of GH with GHBP in the competition binding assay. However, in sequential binding on the BIAcore instrument, they were able to bind GHBP after its interaction with GH, indicating that the inhibition observed in the competition binding assay resulted from steric hindrance rather than direct interference with the GH-binding site of GHBP. The present findings, therefore, suggest that these antibodies are useful for investigating GHBP and its interaction with GH.
研究了针对大鼠生长激素结合蛋白（GHBP）的四条独立单克隆抗体（MAb）系的特性。三种单克隆抗体，命名为GHR - 12、GHR - 13和GHR - 16，是针对完整的GHBP分子产生的。第四种单克隆抗体，命名为GHBP4.3，是针对大鼠GHBP C末端的17个氨基酸残基产生的。通过传统的竞争结合分析和表面等离子体共振，即使用生物特异性相互作用分析（BIAcore）仪器，分析了这些抗体与GHBP的相互作用及其对GH与GHBP结合的影响。这些单克隆抗体与GHBP的结合亲和力范围为29 nmol/l至30.9 pmol/l。在BIAcore上，成对抗体与GHBP的结合表明，GHR - 13和GHR - 16识别不同的抗原决定簇，而GHR - 12表位的一部分可能与其他抗体共享。在竞争结合分析中，这些抗体抑制了GH与GHBP的相互作用。然而，在BIAcore仪器上的顺序结合中，它们能够在GHBP与GH相互作用后结合GHBP，这表明在竞争结合分析中观察到的抑制是由空间位阻引起的，而不是直接干扰GHBP的GH结合位点。因此，目前的研究结果表明，这些抗体可用于研究GHBP及其与GH的相互作用。
