ALPHA-CRYSTALLIN CAN FUNCTION AS A MOLECULAR CHAPERONE
ALPHA-CRYSTALLIN CAN FUNCTION AS A MOLECULAR CHAPERONE
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DOI：
10.1073/pnas.89.21.10449
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发表时间：
1992-11-01
影响因子：
11.1
通讯作者：
HORWITZ, J
中科院分区：
文献类型：
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作者：
HORWITZ, J
α-晶状体蛋白（αA 和 αB）是脊椎动物眼睛的主要晶状体结构蛋白，与小型热休克蛋白家族相关。此外，晶状体蛋白（尤其是 alphaB）存在于晶状体以外的许多细胞和器官中，并且 alphaB 在几种神经系统疾病和应激条件下的细胞系中过度表达。在这里，我展示了 α-晶状体蛋白可以充当分子伴侣。化学计量的 αA 和 αB 抑制热诱导的各种酶的聚集。特别是，α-晶状体蛋白在抑制热诱导的β-和γ-晶状体蛋白（另两种主要的哺乳动物晶状体结构蛋白）的聚集方面非常有效。根据圆二色光谱判断，α-晶状体蛋白还可有效防止聚集和重折叠盐酸胍变性的γ-晶状体蛋白。因此，我的结果表明，α-晶状体蛋白会折射光线并保护蛋白质免于在透明眼晶状体中聚集，并且在非晶状体细胞中，α-晶状体蛋白除了抑制蛋白质聚集的能力外，还可能具有其他功能。
The alpha-crystallins (alphaA and alphaB) are major lens structural proteins of the vertebrate eye that are related to the small heat shock protein family. In addition, crystallins (especially alphaB) are found in many cells and organs outside the lens, and alphaB is overexpressed in several neurological disorders and in cell lines under stress conditions. Here I show that alpha-crystallin can function as a molecular chaperone. Stoichiometric amounts of alphaA and alphaB suppress thermally induced aggregation of various enzymes. In particular, alpha-crystallin is very efficient in suppressing the thermally induced aggregation of beta- and gamma-crystallins, the two other major mammalian structural lens proteins. Alpha-crystallin was also effective in preventing aggregation and in refolding guanidine hydrochloride-denatured gamma-crystallin, as judged by circular dichroism spectroscopy. My results thus indicate that alpha-crystallin refracts light and protects proteins from aggregation in the transparent eye lens and that in nonlens cells alpha-crystallin may have other functions in addition to its capacity to suppress aggregation of proteins.