Catalytic Specific Differences Of Kinds Of Alginate Lyase In Vibrio

To date,several microorganisms that can metabolize alginate have been characterized. In these microorganisms, a class of enzymes called alginate lyases (Alys) catalyze the depolymerization of alginate into oligomers via an endolytic β-elimination reaction. Oligomers are further degraded into unsaturated monomers by an exolytic enzyme known as oligoalginate lyase(Oal),but it is not clear for these lyase members in the enzymology functional differences or division of labor.In recent years, it has become a hot topic in the research for the development and utilization of seaweed which can be treated to alginic acid sodium salt by means of inexpensivement and efficientment. As a member of the seaweed tool enzyme, its major pharmaceutical value and biological researching significance has set up an important position on the biological resources utilization.Aiming at the three identified extracellular secretory alginate lyases in V.alginolyticus ATCC17749, we probed into their the differences of function and the division of labor on substrate specificity, catalytic specificity and apparent properties from the level of protein. Meanwhile,we speculated types of the alginic key and the mutual contents of structure domain between pM and pG in alginate lyase based on the identified hydrolysates of three lyases through the mass spectrometry and nuclear magnetic resonance,and then infering the key amino acids located in catalytic center by means of protein site-directed mutagenesis, and specific amino acid fragments with its exclusive recognitional and catalytic activity effects for different substrates. For the sake of a engineered protein with wide degradation on substrates and high enzyme activity,we reconstructed a series of proteins through splicing. It is of great economic value in our research that can provide theory basis for future inquiry on alginate oligosaccharides transport mechanism and generate a microbial platform that can simultaneously degrade and metabolize alginate for realizing the alginate to ethanol fermentation.