Inhibition of Rhizomucor miehei and Candida rugosa lipases by D-glucose in esterification between L-alanine and D-glucose.
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+/-0.028x10(-3) M h(-1) mg(-1), K(m L-alanine)= 4.9+/-0.51x10(-3) M, K(m D-glucose)=0.21+/-0.018x10(-3) M, and K(i D-glucose)=1.76+/-0.19x10(-3) M; for CRL-k(cat)= 0.75+/-0.08x10(-3) M h(-1) mg(-1), K(m L-alanine)=56.2+/-5.7x10(-3) M, K(m D-glucose)=16.2+/-1.8x10(-3) M, and K(i D-glucose) =21.0+/-1.9x10(-3) M.
Somashekar
Bhandya R
BR
Department of Fermentation Technology and Bioengineering, Central Food Technological Research Institute, Mysore-570020, India.
Lohith
Kenchaiah
K
Manohar
Balaraman
B
Divakar
Soundar
S
D000409:Alanine / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000737:chemistry; D002175:Candida / Q000201:enzymology*; D004951:Esterification; D005656:Fungal Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000302:isolation & purification; D005947:Glucose / Q000737:chemistry; D005960:Glucosides / Q000096:biosynthesis*; D007700:Kinetics; D008049:Lipase / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000302:isolation & purification; D020103:Rhizomucor / Q000201:enzymology*
D005656:Fungal Proteins; D005960:Glucosides; C512749:alanylglucose; D008049:Lipase; D005947:Glucose; D000409:Alanine