Unique kinetics of nicotinic acid-adenine dinucleotide phosphate (NAADP) binding enhance the sensitivity of NAADP receptors for their ligand.
Unique kinetics of nicotinic acid-adenine dinucleotide phosphate (NAADP) binding enhance the sensitivity of NAADP receptors for their ligand.
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烟酸-腺嘌呤二核苷酸磷酸 (NAADP) 结合的独特动力学增强了 NAADP 受体对其配体的敏感性。
DOI：
10.1042/bj3520725
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
A. Galione
中科院分区：
文献类型：
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作者：
S. Patel;G. Churchill;A. Galione
烟酸-腺嘌呤二核苷酸磷酸（NAADP）是一种新型的海胆卵和其他细胞类型中有效的Ca（2+）动员剂。然而，很少有人知道，关于推定的细胞内NAADP受体的性质。在本研究中，我们的特点是在海胆卵匀浆NAADP结合位点。[（32）P]NAADP与一类高亲和力位点结合，该位点可被NaCl可逆抑制，但对pH和Ca（2+）不敏感。[（32）P]NAADP的结合在不动员Ca（2+）响应NAADP的制剂中丢失，表明[（32）P]NAADP可能与介导Ca（2+）动员的受体结合。在[（32）P]NAADP结合开始后的不同时间加入过量的未标记NAADP，不会导致结合[（32）P]NAADP的置换。这些数据表明，NAADP在缔合后立即与其受体不可逆地结合。因此，孵育匀浆与低浓度的NAADP导致NAADP结合位点的最大标记。这种独特的性质使得NAADP受体对其配体非常敏感，从而可以检测NAADP水平的微小变化。
Nicotinic acid-adenine dinucleotide phosphate (NAADP) is a novel and potent Ca(2+)-mobilizing agent in sea urchin eggs and other cell types. Little is known, however, concerning the properties of the putative intracellular NAADP receptor. In the present study we have characterized NAADP binding sites in sea urchin egg homogenates. [(32)P]NAADP bound to a single class of high-affinity sites that were reversibly inhibited by NaCl but insensitive to pH and Ca(2+). Binding of [(32)P]NAADP was lost in preparations that did not mobilize Ca(2+) in response to NAADP, indicating that [(32)P]NAADP probably binds to a receptor mediating Ca(2+) mobilization. Addition of excess unlabelled NAADP, at various times after initiation of [(32)P]NAADP binding, did not result in displacement of bound [(32)P]NAADP. These data show that NAADP becomes irreversibly bound to its receptor immediately upon association. Accordingly, incubation of homogenates with low concentrations of NAADP resulted in maximal labelling of NAADP binding sites. This unique property renders NAADP receptors exquisitely sensitive to their ligand, thereby allowing detection of minute changes in NAADP levels.
环状 ADP-核糖与海胆卵中钙储存微粒体的特异性结合。
DOI：
--
发表时间：
1991
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Lee,HC
通讯作者：
Lee,HC
脑中肌醇三磷酸受体结合的表征。
DOI：
--
发表时间：
1987
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Worley,PF;Baraban,JM;Supattapone,S;Wilson,VS;Snyder,SH
通讯作者：
Snyder,SH