Classifying enzymes from selectivity fingerprints

Fingerprints of lipases and esterases have been recorded by using on array of chiral fluorogenic aliphatic esters of increasing chain length (C-4-C-16) Classification of the enzyme series was carried out with selectivity data by clustering and principal component analysis (PCA). Enzymes were classified on the basis of selectivity for chain length (C-4-C-6 vs, C-10-C-16) and of middle-chain-length (C-8-C-10) reactivity. A minimum set of nine substrates was defined by cluster analysis of relative reactivities of each substrate for the different enzymes. This selectivity-based analysis is general. It does not require a common reference substrate to react with all enzymes or vice versa, and is independent of knowing the exact concentration of active protein in the enzyme samples.