Teschke C M
Department of Molecular and Cell Biology, University of Connecticut, Storrs 06269, USA.
Biochemistry. 1999 Mar 9;38(10):2873-81. doi: 10.1021/bi982739f.
Aggregation is a common side reaction in the folding of proteins which is likely due to inappropriate interactions of folding intermediates. In the in vivo folding of phage P22 coat protein, amino acid substitutions that cause a temperature-sensitive-folding (tsf) phenotype lead to the localization of the mutant coat proteins to inclusion bodies. Investigated here is the aggregation of wild-type (WT) coat protein and 3 tsf mutants of coat protein. The tsf coat proteins aggregated when refolded in vitro at high temperature. If the tsf coat proteins were refolded at 4 degrees C, they were able attain an assembly active state. WT coat protein, on the other hand, did not aggregate significantly even when folded at high temperature. The refolded tsf mutants exhibited altered secondary and tertiary structures and had an increased surface hydrophobicity, which may explain the increased propensity of their folding intermediates to aggregate.
聚集是蛋白质折叠过程中常见的副反应，这可能是由于折叠中间体的不适当相互作用所致。在噬菌体P22外壳蛋白的体内折叠过程中，导致温度敏感折叠（tsf）表型的氨基酸取代会使突变外壳蛋白定位于包涵体中。本文研究了野生型（WT）外壳蛋白和3种外壳蛋白的tsf突变体的聚集情况。tsf外壳蛋白在高温下体外重折叠时会发生聚集。如果tsf外壳蛋白在4℃下重折叠，它们能够达到组装活性状态。另一方面，WT外壳蛋白即使在高温下折叠也不会显著聚集。重折叠的tsf突变体表现出二级和三级结构的改变，并且表面疏水性增加，这可能解释了它们的折叠中间体聚集倾向增加的原因。
