Studies on the alpha-subunit of bovine brain S-100 protein.
Studies on the alpha-subunit of bovine brain S-100 protein.
复制标题
牛脑S-100蛋白α亚基的研究。
DOI：
10.1042/bj2180691
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
H. M. Tice
中科院分区：
文献类型：
--
作者：
H. Masure;J. Head;H. M. Tice
本文介绍了一种用氟奋乃静-琼脂糖亲和柱，以浓度递减的游离Ca~（2+）逐步洗脱，从牛脑粗提物中快速纯化S-100蛋白和钙调素的方法。通过阴离子交换层析从S-100蛋白制备物中纯化仅含α-亚基的蛋白。该蛋白与S-100蛋白的α-亚基在十二烷基硫酸钠/尿素/聚丙烯酰胺凝胶电泳上共迁移，并且具有与先前报道的该亚基相同的氨基酸组成。紫外线的结果-吸收和荧光发射光谱表明，纯化的S-100蛋白α-亚基的色氨酸残基在环境中经历了Ca 2+诱导的变化。色氨酸荧光随Ca2+浓度增加而变化的测量结果表明，在不存在K+的情况下，α亚基对Ca2+的表观解离常数为7 × 10（-5）M。在存在90 mM-K+的情况下，该值增加至3.4 X 10（-4）M。
A method is described for the rapid purification of both S-100 protein and calmodulin from crude bovine brain extracts by the use of a fluphenazine-Sepharose affinity column eluted stepwise with decreasing concentrations of free Ca2+. Protein containing only alpha-subunit was purified from preparations of S-100 protein by anion-exchange chromatography. This protein co-migrated with the alpha-subunit of S-100 protein on sodium dodecyl sulphate/urea/polyacrylamide-gel electrophoresis and had an amino acid composition identical with that previously reported for this subunit. The results of u.v.-absorption and fluorescence-emission spectroscopy indicate that the tryptophan residue of the purified alpha-subunit of S-100 protein undergoes a Ca2+-induced change in environment. Measurements of changes in tryptophan fluorescence with increasing Ca2+ concentrations suggest an apparent dissociation constant of the alpha-subunit for Ca2+ of 7 X 10(-5)M in the absence of K+. In the presence of 90mM-K+ this value is increased to 3.4 X 10(-4)M.