The kinetics of bovine growth hormone folding are consistent with a framework model.

摘要: The framework model of protein folding requires the hydrogen-bonded secondary structure to be formed early in (i.e. formation precedes tertiary structure) (Kim, P. S., and Baldwin, R. L. (1982) Annu. Rev. Biochem. 51, 459-489). To test directly kinetics bovine growth hormone (bGH) were compared utilizing two methods detection, one that measures (far ultraviolet circular dichroism) another (near absorbance). results demonstrate that, under identical conditions, observed by far dichroism are faster than those absorption. indicate existence a helix-containing intermediate which is consistent with model. effect concentration denaturant on refolding studied. rate measured absorbance was dependent concentration. dependence due transient an associated intermediate. taken as evidence sequential process partially folded monomers responsible for association effect. At dilute concentrations can studied independent phenomena. hormones utilized this study derived from Escherichia coli through recombinant DNA technology pituitaries. pituitary-derived bGH has been shown heterogeneous at NH2 terminus (Lorenson, M. F., Ellis, S. (1975) Endocrinology 96, 833-838), whereas DNA-derived contains single terminus. No differences between pituitary derived-bGH observed. It concluded heterogeneity obtained pituitaries does not affect vitro kinetics.