estimase

Estimase is a descriptive term used for enzyme activity that hydrolyzes ester bonds, yielding an alcohol and a carboxylic acid. It is not a formal, universally adopted enzyme name; in many sources esterases are used instead, and specific proteins are usually named after their organism or gene rather than as “estimase.”

Estimases belong to hydrolases (EC 3.1). Many are serine hydrolases with a catalytic triad and an active-site serine that attacks the ester carbonyl, forming an acyl–enzyme intermediate that is subsequently hydrolyzed. Structural motifs commonly observed include alpha/beta hydrolase folds. The substrate scope ranges from small esters to complex natural esters, and some estimases also act on lipid esters, blurring the line with lipases.

In some cases the term is used for a defined esterase from a particular organism, sometimes given a gene name such as estimA. Discoveries occur across bacteria, fungi, plants, and animals, often driven by studies of metabolism, biodegradation, or biocatalysis. Estimases have applications in biocatalysis for ester hydrolysis, enantioselective hydrolysis for pharmaceutical synthesis, and bioremediation of ester-containing pollutants.

In scientific usage, the label estimase should be interpreted with attention to the organism, substrate, and experimental assay, since it is not a fixed taxonomic or functional category.