(A) Rate of absorbance increase at 280 nm for R5P (▲), ribose + Pi (△), dR5P (■), and deoxyribose + Pi (□) with NAcLys at pH 7.4 and 37 °C. (B) Absorbance spectra for R5P (▲), ribose + Pi (△), dR5P (■), and deoxyribose + Pi (□) with NAcLys after 24 h (17.5 h for R5P) at pH 7.4 and 37 °C. (C) Absorbance spectra for three amino acids after a reaction with R5P at pH 8.0 and 37 °C. Reaction time was 10 h for Gly (▲) and Glu (◊), 7.3 h for Asn (■), and 6 h for Gly-Gly (◆).