A detailed kinetic study of the esterification of D-glucose with L-alanine catalyzed by lipases from Rhizomucor miehei (RML) and Candida rugosa (CRL) showed that both lipases follow the Ping-Pong Bi-Bi mechanism, in which L-alanine and D-glucose bind in subsequent steps releasing water and L-alanyl-D-glucose, with competitive substrate inhibition by D-glucose at higher concentrations leading to the formation of dead-end lipase . D-glucose complexes. An attempt to obtain the best fit of this kinetic model through curve fitting yielded good approximates of the apparent values of four important kinetic parameters: for RML-k(cat)=0.29 +/- 0.028 x 10(-3) M h(-1) mg(-1), Km L-alanine = 4.9 +/- 0.51 x 10(-3)M, Km D-glucose=0.21 +/- 0.018 x 10(-3) M, and Ki D-glucose=1.76 +/- 0.19 x 10(-3) M; for CRL-k(cat)= 0.75 +/- 0.08 x 10(-3) M h(-1) mg(-1), Km L-alanine=56.2 +/- 5.7 x 10(-3) M, K-m,K- D-glucose=16.2 +/- 1.8 x 10(-3) M, and Ki D-glucose = 21.0 +/- 1.9 x 10(-3) M.