What is the Difference Between Esterase and Lipase?

Esterase and lipase are both enzymes that hydrolyze ester bonds, but they have distinct differences in their substrate preferences and specificities. Here are the main differences between esterase and lipase:

1. Substrate Specificity: Lipases are mainly active against water-insoluble substrates, such as triglycerides composed of long-chain fatty acids, whereas esterases preferentially hydrolyze 'simple' esters and usually only triglycerides composed of fatty acids shorter than C6.
2. Km Value: Esterases and lipases can be differentiated by their value of Km, which is the substrate concentration at which an enzyme reaches half of its maximum reaction rate.
3. Surface Domain: Lipases, unlike esterases, display a significant difference in the distribution of hydrophobic amino acid residues at the vicinity of the active site, which supports the hypothesis of the existence of a particular surface domain in lipases.
4. Interfacial Activation: Lipases can be distinguished from esterases by the phenomenon of interfacial activation, which is only observed for lipases.
5. Organic Solvent Stability: Both enzymes remain stable in organic solvents, but this property is more noticed for lipases.

Comparative Table: Esterase vs Lipase

Esterase and lipase are both enzymes that hydrolyze ester bonds, but they have distinct differences in their substrate preferences and structures. Here is a table comparing the differences between esterase and lipase:

Esterases preferentially hydrolyze short-chain triglycerides and simple esters, while lipases are more active against long-chain triglycerides and secondary alcohols. Esterases contain more polar amino acids, making them more polar, whereas lipases have more hydrophobic amino acids, making them more non-polar. Esterases are water-soluble, while lipases are soluble in organic solvents. Interfacial activation is observed in lipases but not in esterases. The pH-activity optimum for esterases is typically around 6, while it varies depending on the lipase enzyme.