What distinguishes an esterase from a lipase: A novel structural approach

Esterases and lipases both hydrolyse ester bonds. Whereas the lipases displ ay high activity towards the aggregated state of its substrate, the esteras es typically show highest activity towards the soluble state of its substra te. We have compared the amino acid sequence, the 3D-structure as well as t he pa-dependent electrostatic signature of selected members of the two fami lies, for which 3D-structural information is publicly available. Lipases di splay a statistically significant enhanced occurrence of non-polar residues close to the surface, clustering around the active-site. Lid opening appea rs to strengthen this pattern further. As we have proposed earlier the acti ve site of lipases displays negative potential in the pH-range associated w ith their maximum activity, typically at pH values above 8. The esterases s how a very similar pattern, however, at pH values around 6 correlated with their usually lower pH-activity optimum. (C) 2000 Societe francaise de bioc himie et biologie moleculaire / Editions scientifiques et medicales Elsevie r SAS.