摘要：
As a novel kind of nanomaterial with wide potential applications, the adverse effects of carbon nanotubes (CNTs) have recently received significant attention after respiratory exposure. In this study, single-wall carbon nanotubes (SWCNTs) containing different metal contents were intratracheally instilled into lungs of spontaneously hypertensive rats. Pulmonary and cardiovascular system alterations were evaluated at 24 and 72 h post-instillation. Biomarkers of inflammation, oxidative stress and cell damage in the bronchoalveolar lavage fluid (BALF) were increased significantly 24 h post-exposure of SWCNTs. The increased endothelin-1 levels in BALF and plasma and angiotensin I-converting enzyme in plasma suggested endothelial dysfunction in the pulmonary circulation and peripheral vascular thrombosis. These findings suggest that respiratory exposure to SWCNTs can induce acute pulmonary and cardiovascular responses and individuals with existing cardiovascular diseases are very susceptible to SWCNTs exposure. The co-existence of metal residues in SWCNTs can aggravate the adverse effects.
作者机构：
[Li, Jie; Huang, Chunlin] Univ S China, Sch Pharm & Life Sci, Dept Biochem & Mol Biol, Hengyang 421001, Peoples R China.;[Guo, Bin; Wang, Xiaoying; Zhu, Weitao; Chen, Bo; Yao, Shouzhuo] Hunan Normal Univ, Minist Educ China, Key Lab Chem Biol & Tradit Chinese Med Res, Changsha 410081, Hunan, Peoples R China.;[Ouyang, Shan] Shenzhen Entry Exit Inspect & Quarantine Bur Peop, Food Inspect & Quarantine Ctr, Shenzhen 518067, Peoples R China.
通讯机构：
[Guo, Bin] H;Hunan Normal Univ, Minist Educ China, Key Lab Chem Biol & Tradit Chinese Med Res, Changsha 410081, Hunan, Peoples R China.
关键词：
Animal tissues;Dispersive solid-phase extraction;Multi-residue;Semi-targeted screening;Sulfonamides;Triple-quadrupole linear ion trap mass spectrometer
摘要：
A generic and efficient homolog-targeted approach was used to expand screening and detection of target class of sulfonamides and structural analogs, based on a fast single-tube extraction/partitioning-multifunction adsorption cleanup (SEP/MAC) for class-specific fragmentation-dependent acquisition with a liquid chromatography-hybrid triple-quadrupole linear ion trap mass spectrometer (LC-QqLIT). By combining the two-stage process conducted in a single tube as one-pot protocol, the straightforward SEP/MAC procedure was optimized to offer clean extracts with reasonable recovery (71-109% with RSDs < 20%) and decreased matrix interferences (-9 to 19%) of multiresidual sulfonamide extraction from different tissue samples. The novel use of neutral loss scan of 66 Da (NLS) or precursor ion scanning of m/z 108 (PreS) in positive ion mode was found to achieve more comprehensive coverage of protonated molecular ions of a wide array of sulfonamides including N-4-acetyl and hydroxylamine metabolites plus their possible dimers. Moreover, the PreS-triggered automatically enhanced product ion spectral acquisition enabled simultaneous screening, profiling and confirmation of an unlimited number of analytes belonging to the sulfonamide class within a single analysis. The validation and application results of the generic SEP/MAC-based LC-QqLIT strategy consistently demonstrated favorable performances with acceptable accuracy (67-116%), precision (RSDs < 25%), and sensitivity (LOQs <= 7.5 ng g(-1)) to meet the acceptance criteria for all the sulfonamide-tissue combinations. Thus, the integration of the matrix-independent SEP/MAC procedure and the multiparameter matching algorithm with the unit-resolution LC-QqLIT instrument can serve as a valuable semi-targeted discovery strategy for rapid screening and reliable quantitative/confirmatory analysis of real samples. (C) 2012 Elsevier B.V. All rights reserved.
摘要：
Bovine liver cytochrome b
5 (cyt b
5), with heme bound noncovalently, has been converted into a cyt c-like protein (cyt b
5 N57C) by constructing a thioether linkage between the heme and the engineered cysteine residue. With no X-ray or NMR structure available, we herein performed a molecular modeling study of cyt b
5 N57C. On the other hand, using amino acid sequence information for a newly discovered member of the cyt b
5 family, domestic silkworm cyt b
5 (DS cyt b
5), we predicted the protein structure by homology modeling in combination with MD simulation. The modeling structure shows that both Cys57 in cyt b
5 N57C, and Cys56, a naturally occurring cysteine in DS cyt b
5, have suitable orientations to form a thioether bond with the heme 4-vinyl group, as the heme is in orientation A. In addition to providing structural information that was not previously obtained experimentally, these modeling studies provide insight into the formation of cyt c-like thioether linkages in cytochromes, and suggest that c-type cyt b
5 maturation involves a b-type intermediate.
摘要：
The biological toxicity of uranyl ion (UO
2
2+
) lies in interacting with proteins and disrupting their native functions. The structural and functional consequences of UO
2
2+
interacting with cytochrome b
5 (cyt b
5), a small membrane heme protein, and its heme axial ligand His39Ser variant, cyt b
5 H39S, were investigated both experimentally and theoretically. In experiments, although cyt b
5 was only slightly affected, UO
2
2+
binding to cyt b
5 H39S with a K
D of 2.5 μM resulted in obvious alteration of the heme active site, and led to a decrease in peroxidase activity. Theoretically, molecular simulation proposed a uranyl ion binding site for cyt b
5 at surface residues of Glu37 and Glu43, revealing both coordination and hydrogen bonding interactions. The information gained in this study provides insights into the mechanism of uranyl toxicity toward membrane protein at an atomic level.
作者：
Ling, H. -y.;Hu, B.;Hu, X. -b.;Zhong, J.;Feng, S. -d.;...
期刊：
EXPERIMENTAL AND CLINICAL ENDOCRINOLOGY & DIABETES,2012年120(9):553-559 ISSN：0947-7349
通讯作者：
Liao, D. -f.
作者机构：
[Ling, H. -y.; Hu, B.] Univ S China, Sch Med, Dept Physiol, Hengyang, Peoples R China.;[Liao, D. -f.] Hunan Univ Chinese Med, State Key Lab Chinese Med Powder & Med Innovat Hu, Div Stem Cell Regulat & Applicat, Changsha 410208, Hunan, Peoples R China.;[Ling, H. -y.] Univ S China, Ctr Basic Med Postdoctoral Studies, Hengyang, Peoples R China.;[Hu, X. -b.] Univ S China, Sch Life Sci & Technol, Dept Biochem & Mol Biol, Hengyang, Peoples R China.;[Wen, G. -b.; Zhong, J.] Univ S China, Affiliated Hosp 1, Inst Clin Res, Hengyang, Peoples R China.
通讯机构：
[Liao, D. -f.] H;Hunan Univ Chinese Med, State Key Lab Chinese Med Powder & Med Innovat Hu, Div Stem Cell Regulat & Applicat, Changsha 410208, Hunan, Peoples R China.
摘要：
A novel small molecule probe, aptamer beacon (AB), was introduced for adenosine (Ade) recognition and quantitative analysis. The Ade aptamer was engineered into an aptamer beacon by adding a gold nanoparticle-modified nucleotide sequence which is complementary to aptamer sequence (FDNA) at the 3'-end of FDNA. The fluorescence signal "turning on" was observed when AB was bound to Ade, which is attributed to a significant conformational change in AB from a FDNA/QDNA duplex to a FDNA-Ade complex. The Ade measurement was carried out in 20 mmol L-1 Tris-HCl buffer solution of pH 7.4, Delta F signal linearly correlated with the concentration of Ade over the range of 2.0 x 10(-8) to 1.8 x 10(-6) mol L-1. The limit of detection (LOD) for Ade is 6.0 x 10(-9) mol L-1 with relative standard deviations (R.S.D) of 3.64-5.36%, and the recoveries were 98.6%, 100%, 102% (n = 6), respectively. The present method has been successfully applied to determine Ade in human urine samples, and the obtained results were in good agreement with those obtained by the HPLC method. Our investigation shows that the unique properties of the AB could provide a promising potential for small molecules detection, and be benefit to extend the application of aptamer beacon technique. (C) 2012 Elsevier B.V. All rights reserved.
期刊：
Lipids in Health and Disease,2011年10(1):1-10 ISSN：1476-511X
通讯作者：
Fu, Mingde
作者机构：
[Tian, Li; Fu, Mingde; Liu, Yinghui] Sichuan Univ, W China Hosp, Lab Endocrinol & Metab, Chengdu 610041, Sichuan, Peoples R China.;[Xu, Yanhua] Chengdu Hoist Biotechnol Co LTD, Chengdu 610075, Sichuan, Peoples R China.;[Peng, Tao] Chengdu Univ, Affiliated Hosp Tradit Chinese Med, Chengdu 610072, Sichuan, Peoples R China.;[Long, Shiyin] Univ S China, Dept Biochem & Mol Biol, Hengyang, Hunan, Peoples R China.
通讯机构：
[Fu, Mingde] S;Sichuan Univ, W China Hosp, Lab Endocrinol & Metab, Chengdu 610041, Sichuan, Peoples R China.
关键词：
High Density Lipoprotein;Cholesteryl Ester Transfer Protein;Reverse Cholesterol Transport;High Density Lipoprotein Particle;High Density Lipoprotein Cholesterol Concentration
摘要：
To investigate the effect of triglyceride (TG) integrates with plasma major components of apolipoproteins in HDL subclasses distribution and further elicited the TG-apolipoproteins (apos) interaction in the processes of high density lipoprotein (HDL) mature metabolic and atherosclerosis related diseases. Contents of plasma HDL subclasses were quantities by two-dimensional gel electrophoresis associated with immunodetection in 500 Chinese subjects. Contents of preβ1-HDL, HDL3a, and apoB-100 level along with apoB-100/A-I ratio were significantly increased, whereas there was a significant reduction in the contents of HDL2, apoA-I level as well as apoC-III/C-II ratio with increased TG concentration. Moreover, preβ1-HDL contents is elevated about 9 mg/L and HDL2b contents can be reduced 21 mg/L for 0.5 mmol/L increment in TG concentration. Moreover, with increase of apoA-I levels, HDL2b contents were marginally elevated in any TG concentration group. Furthermore, despite of in the apoB-100/A-I < 0.9 group, the contents of preβ1-HDL increased, and those of HDL2b decreased significantly for subjects in both high and very high TG levels compared to that in normal TG levels. Similarly, in the apoB-100/A-I ≥ 0.9 group, the distribution of HDL subclasses also showed abnormality for subjects with normal TG levels. The particle size of HDL subclasses tend to small with TG levels increased which indicated that HDL maturation might be impeded and efficiency of reverse cholesterol transport(RCT) might be weakened. These data suggest that TG levels were not only significantly associated with but liner with the contents of preβ1-HDL and HDL2b. They also raise the possibility that the TG levels effect on HDL maturation metabolism are subjected to plasma apolipoproteins and apolipoproteins ratios.
摘要：
With more and more potential applications of carbon nanotubes (CNTs) in different fields, the risk of exposure to CNTs is increasing. The interaction between CNTs and protein in biological media can affect the way cells interact with, recognize and process the nanoparticles, and this has important implications for safety considerations. In this study, the interaction of single-walled and multiwall CNTs with various serum proteins was investigated. The adsorption kinetics of protein to CNTs was investigated and a semi-qualitative analysis was provided by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Matrix assisted laser desorption ionization/time of flight mass spectrometry (MALDI-TOF MS) was used to identify the protein species binding to CNTs and atomic force microscopy (AFM) was used to vividly demonstrate the adsorption model of protein on CNTs. All the experimental results showed that the adsorption capacity of CNTs for protein was highly dependent on the type, arrangement model, size and surface modification of CNTs. Significant quantity of proteins in serum could be quickly adsorbed by CNTs, mainly including albumin, prealbumin, transferrin, and immunoglobulin. Noncovalent functionalization of CNTs by polyethylene glycol (PEG) could decrease the protein adsorption on CNTs. These results provide crucial insights into human serum proteins binding to different kinds of CNTs, which is important for understanding the safe application of carbon nanotubes.
关键词：
Human telomerase reverse transcriptase;Lung adenocarcinoma;RNAi;Telomerase;siRNA
摘要：
Human telomerase reverse transcriptase (hTERT) is the catalytic subunit and the activity determinant factor of the telomerase enzyme which maintains the length of human chromosomes. In recent years it has become an attractive molecular target for cancer gene therapy. In the present study, we show that hTERT siRNA effectively suppressed the expression of hTERT mRNA and hTERT protein levels, reduced telomerase activity, and induced apoptosis of A549 lung adenocarcinoma cells (P<0.05). In vivo, tumors treated with the hTERT siRNA were of reduced sizes, indicating that the hTERT siRNA also reduced the tumorigenic potential of lung adenocarcinoma cells (P<0.05). These results demonstrate that hTERT siRNA can cause effective suppression of telomerase and lead to apoptosis in A549 lung adenocarcinoma cells. hTERT siRNA may, therefore, be a strong candidate for highly selective therapy for chemoprevention and treatment of lung adenocarcinoma.
摘要：
Although an affinity tag such as six consecutive histidines, (His)6-tag, has been widely used to obtain high quantity of recombinant proteins, little is known about its influences on heme proteins for lack of structural information. When (His)6-tag was introduced to the N-terminus of a small heme protein, cytochrome b
5, experimental results showed the resultant protein, (His)6-cyt b
5, has similar property and function to that of isolated cyt b
5. To provide structural information for this observation, we herein performed a structural prediction of (His)6-cyt b
5 by molecular modeling in combination with molecular dynamics simulation. The predicted structure, as assessed by a series of criteria with good quality, reveals that the (His)6-tag adopts a helical conformation and packs against the hydrophobic core 2 of cyt b
5 through salt bridges, hydrogen bonding and hydrophobic interactions. The heme group, with the axial His ligands slightly rotated, was found to have similar conformation as in isolated cyt b
5, which indicates that the N-terminal (His)6-tag does not alter the heme active site, resulting in similar dynamics properties for core 1. This study provides valuable information of interactions between (His)6-tag and the rest of the protein, aiding in rational design and application of functional His-tagged proteins.
