[Biochemical properties of extracellular elastase-like protease].

Extracellular elastase-like protease is one of the key virulence proteases of . To date, little is known about this enzyme in terms of genetic information, structure, properties and virulence mechanism due to the difficulties in purification caused by its low secretion amount, high specific activity, uncompleted genome sequencing and annotation. This work investigated the gene, structure and enzymatic properties of this enzyme. The . elastase-like protease from the fungal culture supernatant was analyzed through tandem mass spectrometry (MS/MS) approach, illustrating its primary structure. Bioinformatics tools were employed to predict the conserved domain and tertiary structure, the enzymatic properties were also studied. It turned out that . extracellular elastase-like protease demonstrated well hydrolysis towards elastin and bovine achilles tendon collagen, with of 18.14 μg/s and 17.57 μg/s respectively, better than fish scale gelatin, with the lowest hydrolysis effect on casein. Its activity towards elastin was lower than that of the elastase from porcine pancreas, with values of / of 3.541 (μg/s) and 4.091 (μg/s), respectively. It was an alkaline protease, with optimal pH 8.2 and temperature 37 C. Zn promoted the enzymatic activity while Ca, Mg, Na, elastatinal and PMSF inhibited its activity. Its sequence was similar to secreted serine protease (PDB Entry: c3f7oB_) with multiple conserved fractions each containing more than 7 amino acids, thus suitable for design of PCR primer. This study increased our knowledge on . extracellular elastase-like protease in terms of structure and enzymatic properties, and may facilitate later studies on protein expression and virulence mechanism.