... b-Me-Gal was in the slow exchange regime, whereas that for melibiose and a-Me-Gal, as anomers of lactose and b-Me-Gal,was in the intermediate exchange regime. Thus, the configuration at the hemiacetal ... were calculated from the titration curves measured for the main chain and amide proton groups of Ile102, Ile104, Cys115,Trp117, Lys118 and Gly122, and the side chain nitro-gen and amide proton ... with sugar ligands. Data obtained at 25 °C and pH 6.1 in50 mM of potassium phosphate and a 10% D2O ⁄ 90% H2O mix-ture. The chemical exchange regime in parentheses is based on the observed...