CHARGE AND SOLVATION EFFECTS IN ANION RECOGNITION CENTERS : AN INQUIRY EXPLOITING REACTIVE ARGININES

摘要: Following a long-standing suggestion of Riordan et al. [Riordan, J. F., McElvany, K. D., and Borders, C. L., Jr. (1977) Science 195, 884-885], we sought to exploit chemically activated arginines as probes characterize the microenvironmental effects in enzymes that mediate recognition anionic substrates. A micellar simulation study establishes octylguanidine (OGn) becomes upon incorporation into both cetyltrimethylammonium bromide (CTAB) Triton X-100 micelles activations correlate with pKa diminutions induced its guanidinium group by electrostatic or nonelectrostatic nature reflected results pH salt titration experiments. Next, protein modification modifiable number also have diminished pKa's, again due Warwicker's finite difference Poisson--Boltzmann algorithm [Warwicker, (1992) Mol. Biol. 223, 247-257] is applied several available crystal structure coordinates, indeed, their are found be an microenvironment can diminish magnitudes these matching closely measured experimentally. Finally, examined respect atomic atmosphere thus occur local would facilitate roles anion anchors. Thus, solvation critical determinants arginine role anchor.