作者机构：
[Zeng, Xiao-Xiong; 钟敏; 王晓晴] College of Food Science and Technology, Nanjing Agriculture University, Nanjing 210095, China;[王榆元] College of Chemistry and Chemical Engineering, Nanhua University, Hengyang 421001, China
通讯机构：
College of Food Science and Technology, Nanjing Agriculture University, China
作者机构：
[Lin, Ying-Wu; Sun, Mei-Hui] Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.;[Li, Wei; Tan, Xiangshi] Fudan Univ, Dept Chem, Inst Biomed Sci, Shanghai 200433, Peoples R China.;[Wen, Ge-Bo; Liu, Jiang-Hua] Univ South China, Affiliated Hosp 1, Dept Clin Lab, Hengyang 421001, Peoples R China.;[Wen, Ge-Bo; Lin, Ying-Wu; Liu, Jiang-Hua] Univ South China, Lab Prot Struct & Funct, Hengyang 421001, Peoples R China.
通讯机构：
[Sun, Mei-Hui] U;Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.
摘要：
Although with a distinct heme active site, both myoglobin (Mb) and cytochrome c oxidase (CcO) were found to function as a nitrite reductase (NIR) under hypoxic conditions. On the other hand, Mb was rationally designed to mimic native CcO by introduction of two distal histidines, i.e., L29H/F43H mutant, where His29, His43 and native His64 formed a metal-binding site. To probe the role of distal histidines in regulating the NIR activity of Mb, we herein designed a single mutant of L29H Mb that contains two distal histidines and solved its X-ray crystal structure, then we made both structural and NIR activity comparisons of Mbs with one to three distal histidines. It was shown that introduction of one or two additional distal histidines in Mb leads to the formation of a distal hydrogen network, which slightly alters the conformation of heme active site and inhibits the NIR activity. Meanwhile, the reductase activity of both L29H Mb and L29H/F43H Mb are regulated by metal ions such as Cu(II) or Zn(II) binding to the distal histidines, i.e., Cu(II) enhances the reactivity while Zn(II) inhibits the reactivity. These findings provide valuable insights into the structure and function relationship for both Mb and CcO functioning as a NIR in biological system.
作者机构：
[张红英; 颜雪明] College of Chemistry and Chemical Engineering, University of South China, Hengyang 421001, China;[张红英] Hengyang Finace Economics and Industry Polytechnic, Hengyang 421001, China
通讯机构：
College of Chemistry and Chemical Engineering, University of South China, China
摘要：
Heme proteins perform various biological functions ranging from electron transfer, oxygen binding and transport, catalysis, to signaling. Although adopting proper native states is very important for these functions, progresses in representative heme proteins, including cytochrome c (cyt c), cytochrome b5 (cyt b5), myoglobin (Mb), neuroglobin (Ngb), cytochrome P450 (CYP) and heme-based sensor proteins such as CO sensor CooA, showed that various native functions, or new functions evolved, are also closely associated with non-native states. The structure and function relationship of heme proteins in non-native states is thus as important as that in native states for elucidating the precise roles of heme proteins in biological systems.
作者：
He, F. F.;Wang, H. Q.*;Wang, Y. Y.;Wang, X. F.;Zhang, H. S.;...
期刊：
Journal of Radioanalytical and Nuclear Chemistry,2013年295(1):167-177 ISSN：0236-5731
通讯作者：
Wang, H. Q.
作者机构：
[Wang, X. F.; Wang, H. Q.; He, F. F.; Tang, J. H.; Li, H. L.; Wang, Y. Y.; Zhang, H. S.] Univ S China, Sch Chem & Chem Engn, Hengyang 421001, Hunan, Peoples R China.;[Wang, H. Q.] Univ S China, Sch Chem & Chem Engn, 28 Changsheng W Rd, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Wang, H. Q.] U;Univ S China, Sch Chem & Chem Engn, 28 Changsheng W Rd, Hengyang 421001, Hunan, Peoples R China.
关键词：
Magnetic absorbent;Thorium ion;Imprinted polymers;Schiff base;Separation
期刊：
JOURNAL OF AOAC INTERNATIONAL,2013年96(4):897-901 ISSN：1060-3271
通讯作者：
Peng, Tao
作者机构：
[Nie, Chang-Ming; Xie, Jie; Zhang, Qing-Jie] Univ South China, Dept Chem & Chem Engn, Hengyang 421001, Hunan, Peoples R China.;[Peng, Tao; Chen, Dong-Dong] Chinese Acad Inspect & Quarantine, Agroprod Safety Res Ctr, Beijing 100123, Peoples R China.;[Wang, Xiong] Clover Technol Grp Ltd, Beijing 100044, Peoples R China.;[Wang, Guo-Min] Chongqing Entry Exit Inspect & Quarantine Bur, Chongqing 400020, Peoples R China.
通讯机构：
[Peng, Tao] C;Chinese Acad Inspect & Quarantine, Agroprod Safety Res Ctr, Beijing 100123, Peoples R China.
摘要：
A method based on HPLC with UV detection was developed for the quantitative determination of chloramphenicol (CAP) residues in aquatic products. The samples were extracted with ethyl acetate–ammonium hydroxide (98 + 2, v/v), followed by a cleanup step using an immunoaffinity column. The analytes were determined by HPLC-UV. Optimal conditions for the extraction and cleanup procedures are described. The linear regression equation was y = 91.47x – 8.60 with R2 = 0.9998 (y = peak area and x = CAP concentration) and showed a good reproducibility. The LOQ was 0.25 μg/kg for determining CAP spiked in the aquatic products. The mean recoveries of CAP from fish and shrimp samples fortified at 0.25–1.0 μg/kg were 88.7–93.1 and 92.0–97.3%, respectively; the repeatability RSDs were less than 8.1%. It was concluded that the method is simple, highly sensitive, and low cost for quantitatively measuring CAP residues in aquatic products. Analyte identification was confirmed by HPLC/MS/MS analysis.
