Fingerprint lipolytic enzymes with chromogenic p-nitrophenyl esters of structurally diverse carboxylic acids

A series of structurally diverse chromogenic esters, including a new compound (4-nitrophenyl 2-methylpentanoate), has been synthesized, constituting an array of 17 substrates which could be applied to rapidly fingerprint the activity of lipases or esterases to reveal their substrates specificity and functional characteristics. Combined with genetic technology such as “data mining” and directed evolution, such fingerprints might be a promising platform for discovery of potentially useful enzymes in industrial application. The fingerprint of commercially available Lipase-B from Candida antarctica as a model enzyme was first measured to confirm the reliability of this method. Then three new enzymes mined from genomic libraries were successfully fingerprinted, revealing the functional characteristics of those enzymes. Among them, the enzyme SrfAD was founded with specific substrate preference towards cycloalkyl carboxylic esters and aromatic esters, making it more promising in synthetic utilities than other tested enzymes.