Stoichiometry of GTP hydrolysis and tubulin polymerization.
Stoichiometry of GTP hydrolysis and tubulin polymerization.
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GTP 水解和微管蛋白聚合的化学计量。
DOI：
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发表时间：
1977
影响因子：
11.1
通讯作者：
N. Seeds
中科院分区：
文献类型：
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作者：
R. Maccioni;N. Seeds
通过亲和层析分离并去除可交换核苷酸的羊脑微管蛋白的微管形成需要GTP以获得最大聚合速率和聚合程度。核苷酸类似物鸟苷酰亚甲基二磷酸和鸟苷酰亚氨基二磷酸不能取代GTP;此外，微管相关蛋白和5 M甘油的存在都不能缓解GTP的需求。GTP浓度与微管形成的关系显示缔合常数K = 1 × 10（4）M-1，GDP和鸟苷酰亚胺二磷酸是GTP聚合的竞争性抑制剂。使用快速过滤器测定微管形成，允许早期聚合动力学的定量分析和校正的GTP水解解偶联从微管蛋白聚合，两个分子的GTP水解每摩尔微管蛋白二聚体纳入微管的化学计量已被发现。
Microtubule formation from lamb brain tubulin isolated by affinity chromatography and freed of exchangeable nucleotide requires GTP for maximal rate and extent of polymerization. The nucleotide analogs guanylylmethylenediphosphate and guanylylimidodiphosphate fail to replace GTP; in addition, neither the presence of microtubule associated proteins nor 5 M glycerol relieves the GTP requirement. The relation of GTP concentration and microtubule formation shows an association constant K = 1 X 10(4) M-1; furthermore, GDP and guanylylimidodiphosphate are competitive inhibitors of GTP for polymerization. Using a rapid filter assay for microtubule formation that allows the quantitative analysis of early polymerization kinetics and correcting for GTP hydrolysis uncoupled from tubulin polymerization, a stoichiometry of two molecules of GTP hydrolyzed per mole of tubulin dimer incorporated into microtubules has been found.