Study Of Enzyme Properties In Immobilized Cells And Molecular Accessibility Of Protein

(College of Life Sciences, Wuhan University, Wuhan 430072)The fermentation of RBV enzymatically synthesized , the immobilization of cells with xanthine dehydrogenase in the visible photopolymerisable resin and the relation between accessibility of a protein and its isoelectronic point were studied.A strain of high xanthine dehydrogenase activity was obtained by ions implanted .And it was immobilized in visible photopolymerisable resin .For the degradation of hypoxanthine,the optimal temperature and pH were 35℃ and 8.0 respectively.The xanthine dehydrogenase of the immobilized cells was stable in the pH range of 6.0-8.0 and at temperature below 40℃.The remained activity of the enzyme was 94.99% after ten batches of operation for degradation of hypoxanthine,the average degradation rate of hypoxanthine was 99.19%.The molecular accessibility of enzyme was calculated and analyzed on the basis of its crystal structure data in the PDB.The relations between the accessibility rate(basic amino acids/acid amino acids) and the property of enzyme were discussed,and the relations between the accessibility rate and the isoelectronic point of enzyme were studied,and the linear relation between the accessibility rate and the isoelectronic point was determined,the linear relation between the accessibility rate and the isoelectronic point was discovered.