Using Bacteria-specific Adsorption Screening Role In Protein Research

Method was investigated to extract multiple proteins from complex system including water-soluble fraction of egg yolk and Agkistrodon acutus venom by bacterial specific absorption.Immunoglobulin yolk (IgY) were absorbed directly from water-soluble fraction by streptococcus mutans, then eluted and further purified by columns of thiophilic gel.Based on above experiments of antibody extraction, bacterium cells were applied further to extract interactive proteins from crude venom of Agkistrodon acutus. In aqueous solution, interaction between crude venom and different bacteria including gram-positive bacteria, i.e. streptococcus mutans,streptococcus aureus, and gram-negative bacteria, i.e. E.coliK12, was investigated in detail. Molecule weights of multiple proteins were identified as 110kDa,47kDa, 24kDa, 23kDa and 15kDa by SDS-PAGE, respectively. It had little influence on extraction of snake venom proteins by the same cells of streptococcus mutans even used for 10 cycles.After bacterium cells were treated by formaldehyde, surface proteins of gram-negative bacterium E.coli K12 were eluted little, but it had no influence on adsorption of snake venom proteins to bacterium cells. Treatment by formaldehyde had little influence on snake venom absorption to and deabsorption from gram-positive bacterium streptococcus mutans, but absorbance of interaction protein with molecular weight of 47kDa only adsorbed by streptococcus aureus was greatly decreased.In this paper, one interactive protein was isolated and purified further by ion-exchange chromatography, whose molecular weight was determined by SDS-PAGE to be 24kDa under non-reduced conditions and 25kDa under reduced conditions.