The C-terminal region of alpha-crystallin: involvement in protection against heat-induced denaturation.
The C-terminal region of alpha-crystallin: involvement in protection against heat-induced denaturation.
复制标题
α-晶状体蛋白的 C 末端区域：参与防止热诱导变性。
作者：
Larry J. Takemoto;T. Emmons;Joe HORWITZt
最近的研究表明，α-晶体蛋白可以保护其他蛋白质免受热诱导的变性和聚集。为了确定C-末端区域可能参与这一活动，对α-晶体蛋白进行了有限的胰酶消化，并使用针对这些区域的抗血清评估了α-A和α-B晶体蛋白链的N-末端和C-末端区域的裂解量。有限的胰酶消化只能切割α-A晶状体蛋白的C-末端区域。这种经胰酶处理的α-A晶状体蛋白制剂在体外实验中显示出保护蛋白质免受热诱导聚集的能力降低。综上所述，这些结果表明，α-A晶体蛋白的C-末端区域对于其防止热诱导聚集的能力是重要的，这与已知发生在C-末端区域的翻译后变化可能对α-A晶体蛋白在体内保护蛋白质变性的能力有显著影响的假设是一致的。
Recent studies have demonstrated that the alpha-crystallins can protect other proteins against heat-induced denaturation and aggregation. To determine the possible involvement of the C-terminal region in this activity, the alpha-crystallins were subjected to limited tryptic digestion, and the amount of cleavage from the N-terminal and C-terminal regions of the alpha-A and alpha-B crystallin chains was assessed using antisera specific for these regions. Limited tryptic digestion resulted in cleavage only from the C-terminal region of alpha-A crystallin. This trypsin-treated alpha-A crystallin preparation showed a decreased ability to protect proteins from heat-induced aggregation using an in vitro assay. Together, these results demonstrate that the C-terminal region of alpha-A crystallin is important for its ability to protect against heat-induced aggregation, which is consistent with the hypothesis that post-translational changes that are known to occur at the C-terminal region may have significant effects on the ability of alpha-A crystallin to protect against protein denaturation in vivo.