Calcium Binding Properties of γ-Crystallin
Calcium Binding Properties of γ-Crystallin
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γ-晶状体蛋白的钙结合特性
DOI：
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发表时间：
2001
影响因子：
4.8
通讯作者：
Y. Sharma
中科院分区：
文献类型：
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作者：
B. Rajini;P. Shridas;C. Sundari;D. Muralidhar;S. Chandani;F. Thomas;Y. Sharma
β-和γ-晶体蛋白是βγ-晶体蛋白超家族中密切相关的晶状体蛋白，该家族还包括许多非晶状体成员。虽然已知β-晶体蛋白是一种钙结合蛋白，但γ-晶体蛋白的这一特性尚未见报道。我们研究了γ-晶体蛋白的钙结合性质，结果表明，它能结合4moleq的钙，解离常数为90μm，还能结合模拟钙的光谱探针、Tb和染料-ALL。钙结合不会显著影响蛋白质的二级和三级结构。我们提供的证据表明，希腊关键的晶体蛋白折叠是γ-晶体蛋白中钙离子结合的部位。合成了与γ-晶体蛋白希腊关键基序(42个残基)相对应的多肽及其突变体，并对其钙结合进行了研究。这些多肽采用β-Sheet构象，形成聚集体，形成β-三明治。我们对多肽的研究结果表明，在希腊的关键基序中，“a”链保守的芳香角附近的氨基酸和“d”链的三个氨基酸参与了钙结合。我们认为βγ超家族代表了一类新的钙结合蛋白，希腊关键的βγ-晶体蛋白折叠是潜在的钙结合位点。这些结果对于理解晶状体内钙稳态的机制具有重要意义。
The β- and γ-crystallins are closely related lens proteins that are members of the βγ-crystallin superfamily, which also include many non-lens members. Although β-crystallin is known to be a calcium-binding protein, this property has not been reported in γ-crystallin. We have studied the calcium binding properties of γ-crystallin, and we show that it binds 4 mol eq of calcium with a dissociation constant of 90 μm. It also binds the calcium-mimic spectral probes, terbium and Stains-all. Calcium binding does not significantly influence protein secondary and tertiary structures. We present evidence that the Greek key crystallin fold is the site for calcium ion binding in γ-crystallin. Peptides corresponding to Greek key motif of γ-crystallin (42 residues) and their mutants were synthesized and studied for calcium binding. These peptides adopt β-sheet conformation and form aggregates producing β-sandwich. Our results with peptides show that, in Greek key motif, the amino acid adjacent to the conserved aromatic corner in the “a” strand and three amino acids of the “d” strand participate in calcium binding. We suggest that the βγ superfamily represents a novel class of calcium-binding proteins with the Greek key βγ-crystallin fold as potential calcium-binding sites. These results are of significance in understanding the mechanism of calcium homeostasis in the lens.
钙调蛋白与羰花青染料 (Stains-all) 的相互作用。
DOI：
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发表时间：
1985
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Caday,CG;Steiner,RF
通讯作者：
Steiner,RF
使用位点特异性诱变表征黄色粘球菌发育特异性蛋白 S 中的钙结合位点。
DOI：
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发表时间：
1988
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Teintze,M;Inouye,M;Inouye,S
通讯作者：
Inouye,S