Figure 2. Effect of arginine hydrochloride on thiol group accessibility

Accessibility or reactivity of the thiol group of the cysteine residue of bovine α-crystallin (A) and human recombinant αA-crystallin (B) to the Ellman's reagent (DTNB) at 37 °C. In both the panels the accessibility of the protein thiol group in buffer alone (open circle) in buffer containing 200 mM Arg·HCl (closed circle), 200 mM Lys·HCl (open square) and 200 mM glycine (closed square). The inset in A shows the effect of various concentrations of Arg·HCl on the accessibility of the thiol group of bovine α-crystallin at 37 °C. The fractional accessibility of thiol in bovine α-crystallin was calculated using a 3:1 molar ratio of the αA-crystallin and αB-crystallin subunits in the hetero assembly [42].