Objectives: Ustilago maydis lipase A (UMLA) expressed in Pichia pastoris was compared with Candida antarctica lipase A (CALA) to study its biochemical properties such as thermostability and selectivity.
Results: UMLA had similar behavior to its homologue CALA regarding the effect of pH and temperature on enzymatic activity, substrate preference and selectivity. Both lipases were active on insoluble triglycerides as well as natural oils and hydrolyzed preferably esters with short and medium acyl and alkyl chains. Both enzymes were slightly selective for the (S)-glycidyl butyrate enantiomer and had a remarkable preference for the sn-2 position of triglycerides. The optimal activity was 40 and 50 °C for UMLA and CALA, respectively. However, temperature had a greater effect on the stability of UMLA compared to CALA, observing a half-life at 50 °C of 2.07 h and 12.83 h, respectively.
Conclusions: UMLA shares some biochemical properties with CALA such as the sn-2 preference on triglyceride hydrolysis and transesterification. However, the high thermostability attributed to CALA was not observed in UMLA; this can be due to the lack of stabilization via AXXXA motifs in helices and fewer proline residues at the surface.
Keywords: Candida antarctica; Lipase; Pichia pastoris; Thermostability; Ustilago maydis; sn-2-Selectivity.