In collaboration with the group of Prof. Fernández-Lobato at CBMSO (UAM-CSIC), we have investigated three new chitinases from M. pulcherrima, MpChit35, MpChit38 and MpChit41. They were molecularly characterized and extracellularly expressed in Pichia pastoris.The three enzymes hydrolysed colloidal chitin with optimal activity at 45 ºC and pH 4.0-4.5, The partial separation and characterization of the complex COS mixtures produced from the hydrolysis of chitin and chitosan were achieved by a new anionic chromatography HPAEC-PAD method and mass spectrometry assays. An overview of the predicted structures of these proteins and their catalytic modes of action were also presented. Depicted their high sequence and structural homology, MpChit35 acted as an exo-chitinase producing di-acetyl-chitobiose from chitin while MpChit38 and MpChit41 both acted as endo-chitinases producing tri-acetyl-chitotriose as main final product.
Microbial Cell Factories 23, 31 (2024) https://doi.org/10.1186/s12934-024-02300-9