The allosteric transition of the insulin hexamer is modulated by homotropic and heterotropic interactions.

摘要: The allosteric behavior of the Co(II)-substituted insulin hexamer has been investigated using electronic spectroscopy to study binding different phenolic analogues and singly charged anions effector sites on protein. This work presents first detailed, quantitative analysis ligand-induced T- R-state transition hexamer. Recent studies have established that there are two ligand processes which stabilize conformation hexamer: cyclic organic molecules six protein pockets present in Zn(II)-R6 [Derewenda, U., Derewenda, Z., Dodson, E. J., G. G., Reynolds, C. D., Smith, Sparks, C., & Swensen, D. (1989) Nature 338, 594-596] coordination His(B10) metal [Brader, M.L., Kaarsholm, N.C., Lee, W.K., Dunn, M.F. (1991) Biochemistry 30, 6636-6645]. R6 is stabilized by heterotropic interactions between hydrophobic His(B10)-bound ions. with 4-hydroxybenzamide, m-cresol, resorcinol, phenol presented herein show that, absence inorganic anions, 4-hydroxybenzamide-induced transition, a Hill number 2.8, most cooperative, followed phenol, resorcinol numbers 1.8, 1.4, 1.2, respectively. relative effectiveness these ligands shifting equilibrium favor Co(II)-R6 was found be > 4-hydroxybenzamide m-cresol.(ABSTRACT TRUNCATED AT 250 WORDS)