Versatile Lipases from the Candida rugosa-like Family: A Mechanistic Insight Using Computational Approaches

Lipases
are enzymes able to catalyze the hydrolysis or synthesis
of triglycerides, depending on the reaction conditions, whereas sterol
esterases show the same ability on sterol esters. Structurally, both
kinds of enzymes display an α/β-hydrolase fold, with a
substrate-binding pocket formed by a hydrophobic cavity covered by
a mobile lid. However, it has been reported that some lipases from
the Candida rugosa-like family display
wide substrate specificity on both triglycerides and sterol esters.
Among them, enzymes with different biotechnological applications,
such as the lipase isoenzymes produced by C. rugosa and the sterol esterase from Ophiostoma piceae, have been exhaustively characterized and their crystal structures
are available. Differences in substrate affinity among these proteins
have been attributed to changes in their hydrophobicity. In this work,
we analyzed the full catalytic mechanisms of these proteins using
molecular dynamics tools, gaining insight into their mechanistic properties.
In addition, we developed an in silico protocol to
predict the substrate specificity using C. rugosa and O. piceae lipases as model enzymes
and triglycerides and cholesterol esters with different fatty acid
chain lengths as model substrates. The protocol was validated by comparing
the in silico results with those described in the
literature. These results would be useful to perform virtual screening
of substrates for enzymes of the C. rugosa-like family with unknown catalytic properties.