Relationship of fluorescence quenching effect of 8-alkyl-berberine homologues on bovine serum albumins and their antimicrobial activities
AIM:To investigate the relationship of antimicrobial activity and fluorescence quenching effect of 8-alkyl-berberine bomologues(Ber-C8-n)including berberine,8-ethyl-berberine,8-butyl-berberine,8-hexyl-berbefine,8-octyl-berbefine,8-decylberberine,8-dodecyl-berberine and 8-cetyl-berberine on protein and the changing mechanism of antimicrobial activity.METHODS:With bovine serum albumins(BSA)as experimental material and phosphate buffered sMine(PBS)as reacting solvent,the fluorescence intensity of Tryptophan(Trp),Tyrosine (Tyr)and Phenylalanine(Phe)residues in BSA were determined after BSA reacted with Ber-C8-n of different concentration in PBS system.RESULTS:The fluoreseenee quenching effects of all Ber-C8-n on BSA were observed,which exhibited obvious doseeffect relationship.The parabolic law of fluorescence quenching effects of Ber-C8-n on Trp,Tyr and Phe residues in BSA was also find out,which was the same as the parabolic law of antimierobial activity of Ber-C8-n.For example,the 8-octyl-berberine having highest antimicrobial activity among Ber-C8-n showed strongest fluorescence quenching ability on BSA,and too short or too long substituted alkyl chain at C8 position of berberine decreased their fluorescence quenching ability and antimierobial activity.Besides,the fluorescence quenching effect of Ber-C8-n.on Trp residue far higher than on Tyr and Phe residues of BSA.CONCLUSION:Results indicated the antimicrobial activity of Ber-C8-n is higher,the fluorescence quenching ability is stronger,and antimicrobial activities of Ber-C8-n were related to their ability of combining with rich Trop resides region of target protein.
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万方数据
维普
