Pathway of Oxidative Folding of a 3-Disulfide α-Lactalbumin May Resemble Either BPTI Model or Hirudin Model

摘要: Pathways of oxidative folding disulfide proteins display a high degree diversity and vary among two extreme models. The BPTI model is defined by limited species intermediates adopting mainly native bonds. hirudin characterized highly heterogeneous containing mostly non-native αLA-IIIA 3-disulfide variant α-lactalbumin (αLA) with 3-D conformation essentially identical to that intact αLA. contains 3 bonds αLA, them are located at the calcium binding β-subdomain (Cys61–Cys77 Cys73–Cys91) third bridge within α-helical domain molecule (Cys28–Cys111). We investigate here pathway fully reduced without stabilization its binding. In absence calcium, was shown resemble model. Upon β-sheet binding, exhibits striking similarity Three predominant exclusively were isolated structurally characterized. Our results further demonstrate subdomains in protein may dictate represent major cause for existing pathways disulfide-containing proteins.