Recently,there are also great interests in the interaction of bacteria with TiO,but the antibacterial behavior...
Yuesheng Lia~b,Xiaole Han~a,Meifang Zhang~a,Yue Zhang~a,Aiqing Zhang~c, Fenglei Jiang~a,Yi Liu~(a,*) a State Key Laboratory of Virology & Key Laboratory of Analytical Chemistry for Biology and Medicine of the Ministry of Education,College of Chemistry and Molecular Sciences,Wuhan University,Wuhan 430072,P.R.China b Department of Chemistry and Life Sciences,Xianning University,Xianning 437005,P.R.China c Key Laboratory of Catalysis and Materials Science of Hubei Province,South-Central Nationalities University,Wuhan 430074,P.R.China
The interaction between Methylene Blue(MB)/TiO nanocomposites and bovine serum albumin(BSA) was investigated b...
Yuesheng Li~(a,b),Ran Li~a,Jianghan~a,Dongwei Li~a,Aiqing Zhang~c,Fenglei Jiang~a,Yi Liu~(a,*) a College of Chemistry and Molecular Sciences,Wuhan University,Wuhan 430072,P.R.China
The interaction between 3-thiol-4-(2,4-dichlorobenzylideneamino)-5-methyl-4H-1,2,4-triazole (CBTZ) and bovine serum albumin (BSA) under physiological conditions was investigated by fluorescence,UV-vis absorption and circular dichroism (CD) spectroscopy as well as molecular modeling methods. The result of fluorescence experiment indicates the static quenching as a result of the formation of the CBTZ-BSA complex. The binding constants (Ka) at different temperatures were calculated according to the modified Stern-Volmer equation. The enthalpy change (-H) and entropy change (-S) were determined based on the van′t Hoff equation. Both negative-H and-S indicated that van der Waals and hydrogen-bonding forces were the dominant intermolecular forces to stabilize the CBTZ-BSA complex. Site marker competitive replacement experiments demonstrated that binding of CBTZ to BSA primarily took place in sub-domain IIA (Sudlow's site I). The binding distance (r = 7.2 nm) between CBTZ and the tryptophan residue of BSA was estimated according to the theory of fluorescence resonance energy transfer (FRET). The conformational studies by circular dichroism (CD) and three-dimensional fluorescence spectroscopy showed that the presence of CBTZ induced minor changes of the secondary structure of BSA. Molecular modeling study further confirmed the binding mode obtained experimentally.
FU JiaXinWANG KaiWeiGE YuShuJIANG FengLeiSUN XiaoHongLIU YangLIU Yi
The growth of Staphylococcus aureus under the action of six kinds of Schiff bases（A,B,C,D,E,F） was studied by means of microcalorimetry. Growth constant k and inhibition ratio I were calculated. Also,the antibacterial activity,the action characteristics and the structure-activity relationships of the compounds on S. aureus were analyzed. Results indicate that B,F show good antibacterial activity（IC50：293.6 mg · L-1 and 307.8 mg · L-1） ,D,E show moderate antibacterial activity（IC50：966.3 mg · L-1 and 1 126.7 mg · L-1） ,and A,C just show weak antibacterial activity（IC50 〉1 200 mg · L-1） . The I-c curves mainly present a straight line shape for B,D,E and F,but an inverse ＂S＂ shape for A and C. Structure-activity relationships analysis suggests that the species and position of the substituents determine the antibacterial activity of these Schiff bases,and the charge density distribution is one of the most important influencing factors.
HOU HannaZHU JunchengQI ZudeZHOU BoLI MeiyingLIU Yi
