Effect of deposition potential and concentration of electroactive substances on Bi2Te3 nanowires fabricated by electrochemical method.

In this paper, Bi2Te3 nanowires were prepared in anodized aluminum oxide template by electrochemical deposition. The morphological microstructural and electrical resistance characteristics of the nanowires were discussed to reveal the effect of deposition potential and electroactive substance (HTeO2 +) concentration. According to the electrode dynamics formula, it is found that the increase of electrode potential leads to the decrease of deposition current, so that deposition rate of nanowires decreases. At the same time, the deposition current controlled by diffusion in the mass transport process will have a maximum value with the increasing of deposition time. The deposition potential determines the favorable crystal plane for nanowires growth by the selection of proper surface energy. The temperature dependence of resistances in Bi2Te3 nanowires fabricated under different concentration of HTeO2 + reveals the transformation of the carriers' main scattering mechanism. This study could provide a better understanding of the deposition process of Bi2Te3 nanowires.

Correlations between DHT/AR and ATAD2 expression in hepatocellular carcinoma / 中华肝胆外科杂志

Objective To investigate the expression of androgen receptor(AR),ATAD2 in hepatocellular carcinoma(HCC) and the correlations with clinicopathological features,and the role of DHT/AR and ATAD2 in proliferation of HCC cells.Methods The samples of 75 patients with HCC in the First Affiliated Hospital of China Medical University from February 2012 to December 2012 were collected.LM3 and Huh7 cells were divided into control group,DHT group,DHT + CDX (bicalutamide) group and CDX group;and also divided into Ri-ATAD2 group (adding interference fragments) and Ri-C group (adding control vector sequence).Immunohistochemistry was used to detect the expression of AR and ATAD2,and to analyze the correlations between clinical features and survival of patients.Real-time PCR and Western Blot were used to detect the expression of AR and ATAD2,and CCK-8 was used to detect cell proliferation.Results HCC patient samples were grouped according to AR and ATAD2 expression.Compared with low AR expression group (n =31),the ratio of tumor ＜5 cm in high expression group (n =44) was higher,and the ratio of TNM stage Ⅰ + Ⅱ was lower.Compared with low ATAD2 expression group (n=35),the ratio of metastasis and tumor differentiation grade Ⅲ + Ⅳ was higher in high expression group (n=40),and the difference was statistically significant (P ＜ 0.05).The overall survival rate of patients with high expression of ATAD2 was lower than other patients,and the differences were statistically significant (P＜0.05).Multivariate Cox regression analysis showed that ATAD2 expression (HR=1.935,95％ CI:1.066～3.515) and metastasis (HR=2.212,95％ CI:1.059～4.619) were independent predictors of poor prognosis.Compared with LO2 cells,the mRNA and protein level of AR and ATAD2 in LM3 and Huh7 cells were significantly higher,and the differences were statistically significant (P＜0.05).And the proliferation rate of HCC cells increased significantly after 48 and 72 hours compared with the control group,and the differences were statistically significant (P＜0.05).After adding CDX,the proliferation of LM3 and Huh7 induced by DHT was inhibited.DHT enhanced the expression of ATAD2,while CDX inhibited the expression of ATAD2.The expression of ATAD2 protein decreased when LM3 and Huh7 cells were interfered.Compared with Ri-C group,the proliferation of HCC cells in Ri-ATAD2 group decreased significantly after the DHT treatment 48 and 72 hours,and the difference was statistically significant (P＜0.05).Conclusions DHT/AR promoted the proliferation of HCC cells by inducing ATAD2 expression.Modulating ATAD2 expression may be the potential mechanism of DHT/AR in HCC proliferation.

Expression and identification of an antimicrobial peptide VIP in Pichia pastoris / 生物工程学报

With the sequence of the vasoactive intestinal peptiepeptide (VIP) from humans and according to the condon bias of Pichia pastoris, we designed PCR primers of VIP and obtained the sequence of VIP by SOE-PCR. Then VIP gene was cloned into Pichia pastoris secretory expression vector and the cell secretary system GS115-pPICZαA-vip was constructed. The recombinant strain was induced by methanol for 96 hours, and we collected the supernatant and identified the VIP by mass spectrometry. The molecular weight of VIP was consistent with theoretical molecular weight. The final result showed that the target peptide VIP was successfully expressed. The experimental investigations of agarose gel diffusion revealed that the recombinant expression modified VIP had relatively strong antibacterial activity to E. coli ATCC25922 and S. aureus ATCC25923. The minimal inhibitory concentration (MIC) of VIP to E. coli ATCC25922 and S. aureus ATCC25923 was 8 mmol/L and 16 mmol/L. Further cytotoxicity and hemolytic experiments indicated that recombinant VIP was non-toxic to normal cells NCM460 and IPEC-J2, had little hemolysis activity to SD rat erythrocytes. Meanwhile, by transmission electron microscopy, we found that VIP mainly inhibited bacteria by disrupting the cell membrane. These experiments established a useful system for further studies, application and mass production of antimicrobial peptide VIP.

Effectiveness and Safety of Escitalopram and Duloxetine in the Treatment of Depression:a Meta-analysis / 中国药房

OBJECTIVE:To systematically evaluate the effectiveness and safety of escitalopram and duloxetine in the treatment of depression, and provide evidence-based reference for clinical treatment. METHODS:Retrieved from PubMed, Wanfang database,VIP,CNKI and CBM,randomized controlled trials (RCTs) about escitalopram (trial group) and duloxetine (control group) in the treatment of depression were collected. Meta-analysis was conducted by using Rev Man 5.3 software after data extraction and quality evaluation according to bias risk assessment tool recommended by system evaluator manual 5.3. RESULTS:Finally 25 RCTs were included,involving 2621 patients. The results of Meta-analysis showed that there was no statistical significance in total response rate between 2 groups after 1,2,4,6,8 weeks of treatment or cure rate between 2 groupsafter 4,6,8 weeks of treatment (P>0.05). There was no statistical significance in total response rate [RR=0.96,95％CI(0.88, 1.05),P=0.42] or cure rate [RR=0.91,95％CI(0.78,1.06),P=0.24] of female patients,as well as total response rate [RR=0.96, 95％CI(0.84,1.11),P=0.61] or cure rate [RR=0.90,95％CI(0.54,1.49),P=0.69] of elderly patients between 2 groups. The incidence of constipation [RR=0.59,95％CI (0.42,0.81),P=0.001],dry mouth [RR=0.65,95％CI(0.51,0.82),P=0.0004], nausea [RR=0.68,95％CI(0.56,0.83),P=0.0002] and decreased appetite [RR=0.74,95％CI(0.55,0.99),P=0.04] in trial group were significantly lower than control group,with statistical significance. CONCLUSIONS:The effectiveness of escitalopram is similar to duloxetine in the treatment of depression,but the safety of escitalopram is better than duloxetine.

Impact of eotaxin-3 gene polymorphisms on inhaled corticosteroids in patients with bronchial asthma / 重庆医学

Objective To investigate the impact of eotaxin-3 gene polymorphisms on the clinical effect of inhaled corticosteroids (ICS) to provide clinical basis for eotaxin-3 as the target spot for treating bronchial asthma.Methods One hundred and ninety-six cases of asthma and 196 cases as controls were selected from the outpatients and inpatients in our hospital.Peripheral blood samples were collected from the asthma patients and normal controls.PCR-RFLP was adopted to detect the genotypes of eotaxin-3 +2497T＞G and-+-77C＞T.The response of ICS treatment and the change situation of ACT scores were compared among asthmatic patients with various genotypes.Results Peripheral blood eosinophil(EOS) counts,EOS proportion and total IgE in the patients with TG genotype at+2497 locus were significantly decreased compared with those in the patients with TT genotype,the difference was statistically significant(P＜0.05).The level of PD20 in asthmatic patients with TG genotype was significantly higher than that in the patients with TT genotype,the difference was statistically significant[(0.07-±-0.03)mg vs.(0.03 ± 0.01)mg,t=2.45,P=0.048];whereas the above indicators had no statistical difference among 3 kinds of +-77 genotypes.During ICS treatment process in the patients with TT genotype at +-2497 locus,the FEV1％,PD20 value and ACT scores were significantly improved compared with those in the patients with TG genotype,the difference was statistically significant(P＜0.01).Conclusion The asthmatic patients with TT genotype at +-2497 locus were more sensitive to ICS treatment,regular ICS treatment can significantly improve the lung function and clinical symptom score in these patients.

Impact of eotaxin-3 gene polymorphisms on inhaled corticosteroids in patients with bronchial asthma / 重庆医学

Objective To investigate the impact of eotaxin-3 gene polymorphisms on the clinical effect of inhaled corticosteroids (ICS) to provide clinical basis for eotaxin-3 as the target spot for treating bronchial asthma.Methods One hundred and ninety-six cases of asthma and 196 cases as controls were selected from the outpatients and inpatients in our hospital.Peripheral blood samples were collected from the asthma patients and normal controls.PCR-RFLP was adopted to detect the genotypes of eotaxin-3 +2497T＞G and-+-77C＞T.The response of ICS treatment and the change situation of ACT scores were compared among asthmatic patients with various genotypes.Results Peripheral blood eosinophil(EOS) counts,EOS proportion and total IgE in the patients with TG genotype at+2497 locus were significantly decreased compared with those in the patients with TT genotype,the difference was statistically significant(P＜0.05).The level of PD20 in asthmatic patients with TG genotype was significantly higher than that in the patients with TT genotype,the difference was statistically significant[(0.07-±-0.03)mg vs.(0.03 ± 0.01)mg,t=2.45,P=0.048];whereas the above indicators had no statistical difference among 3 kinds of +-77 genotypes.During ICS treatment process in the patients with TT genotype at +-2497 locus,the FEV1％,PD20 value and ACT scores were significantly improved compared with those in the patients with TG genotype,the difference was statistically significant(P＜0.01).Conclusion The asthmatic patients with TT genotype at +-2497 locus were more sensitive to ICS treatment,regular ICS treatment can significantly improve the lung function and clinical symptom score in these patients.

Clinical nursing research: a novel method to assess the misplacement of peripherally inserted central catheter / 中国实用护理杂志

Objective To explore a new method which could detect the misplacement of peripherally inserted central catheter (PICC).Methods The action of coughing was applied to 252 patients and observing the changes in dripping speed.Results The accuracy rate of this new method was 100.00％ (252/252).The success rate of first PICC in these patients was also 100.00％ (252/252).Conclusions It suggests that the new method Should be effective and convenient in the assessment of PICC misplacement and it can be applied to detect the misplacement occurred in and after the process of PICC.

Comparison of dezocine and fentanyl on immune status and serum levels of inflammatory cytokines of patients with breast cancer after surgery / 中国生化药物杂志

Objective To discuss comparison of different analgesic solution to the immune status and serum levels of inflammatory cytokines of the patients with breast cancer after surgery.Methods The patients of experimental group and control group were given Dizocine and fentanyl to analgesic respectively perioperative experimental.Then analysis and comparison the immune status and serum levels of the two groups.Results The T lymphocyte subsets ( The level of CD3 +、CD4 +and the ratio CD4 +/CD8 +) and the level fo NK cells of the exprimental group patients intraoperative and postoperative 1 d were significantly higer than the control group.The anti-inflammatory factor in the serum of the experimental group patients intraoperative and postoperative 1d was significantly higer than the control group.The proinflammatory factor in the serum of the experimental group patients intraoperative and postoperative 1 d was significantly lower than the control group.Conclusion Dizocine can significantly improve the serum inflammatory factors of the patients with brest cancer after surgery,and can adjust the patient’s immune status.

Progresses on reirradiation for locally recurrence of non-small-cell lung cancer patients after radio-therapy and chemotherapy / 实用肿瘤学杂志

The recurrence rate of non -small cell lung cancer ( NSCLC) patients after radiotherapy and chemotherapy have been increasing .The therapy scheme consists of reirradiation、chemotherapy、and chemoradio-therapy,with the purpose of improving the local control and prolonging the survival time .Reirradiation is feasible for locally recurrence of non -small-cell lung cancer patients , treatment is security and could better improve quality of life in patients .The majority of patients are tolerable and have better short -term efficacy , No severe short term radiation induced injury is observed .But the long term radiation induced injury and long term efficacy need further investigation .In the present paper ,we review the roles of reirradiation for locally recurrence of non -small-cell lung cancer patients after radiotherapy and chemotherapy and the progress in clinical research .

Relationship between Helicobacter pylori infection and gastric carcinogenesis in elderly patients / 中华老年医学杂志

Objective To explore the relationship between Helicobacter pylori (HP) infection and gastric carcinogenesis,and to investigate its mechanism.Methods Totally 333 elderly patients with different degrees of gastric mucosal lesions in our hospital were selected.Patients were divided into 4 groups:chronic superficial gastritis group (n=86),chronic atrophic gastritis group (n=92),gastric ulcer group (n=80) and gastric cancer group (n=75).HP infection in patients were detected by paraffin-embedded tissue sections and ELISA.The gene expressions of c-myc,p16 and p53 were detected by immunohistochemical SP method,and the results were analyzed.Results HP infection positive rate was significantly higher in gastric cancer group than those in the chronic superficial gastritis group and chronic atrophic gastritis group (both P＜ 0.05).There were no significant differences in the expression rates of c-myc,p16 and p53 between HP positive and negative patients in chronic superficial gastritis group (all P＞0.05).There were differences in the expression rates of cmyc and p53 (both P＜0.05),while the expression rate of p16 had no significant difference between HP positive and negative patients in chronic atrophic gastritis group (P ＞ 0.05).There were differences in the expression rates of c-myc,p16 and p53 between HP positive and negative patients in gastric ulcer group and gastric cancer group (all P ＜ 0.05).Conclusions There is a certain correlation between Helicobacter pylori infection and gastric carcinogenesis.It is important to take anti-inflammatory treatment timely and actively to prevent gastric cancer in patients with HP infection in gastric mucosal lesions.

The clinical analysis of postoperative complications reasons of ventriculoperitoneal shunt surgery in infants / 中国医师进修杂志

Objective To analyze the complications ofventriculoperitoneal shunt in the treatment of pediatric hydrocephalus,and improve operative method,in order to reduce postoperative complications and improve the clinical curative effect.Methods A total of 39 infants with hydrocephalus who underwent adjustable shunt were retrospectively analyzed,including surgical methods,results,and complications,and put forward counter measures.Results Thirty cases of postoperative clinical symptoms obviously improved compared with preoperative,head CT review were clearly seen with ventricle retraction.Nine cases suffered with complications after operation.Obstruction of shunt tube was found in 4 cases,shunt exposed in 3 cases,and postoperative infection in 2 cases.Conclusions Ventriculoperitoneal shunt complications related to surgery itself.Improved surgical techniques,and taking appropriate treatment measures can effectively reduce the incidence of complications.

Biological safety evaluation of 125I-filled carbon nanotubes covered with metallic esophageal stent / 中华放射医学与防护杂志

Objective To evaluate the biological safety of 125I-filled carbon nanotubes covered with metallic esophageal stent with regard to the normal esophagus before clinical application.Methods 125I-filled carbon nanotubes covered with metallic esophageal stent was prepared.Eighteen of New Zealand rabbits were randomly divided into three groups with 6 rabbits in each group.Three groups of stents,non-radioactive,low radio-activity ( 3.7 - 5.6 MBq),and high activity ( 11.1 - 13.0 MBq ) were placed in the midpiece of esophagus of rabbits.Esophagus opacification and three-diamensions DSA were performed at 0.5 h,7,14 and 30 d after insertion of the stents,respectively.The rabbits were killed at 30d after insertion of the stents,and histologic examinations of the esophageal walls were performed.Results In non-radioactive and low activity groups,1 of 6 rabbits died of wound infection at 1 and 3 d after surgery due to pulmonary infection,respectively.All specimens were obtained from 16 rabbits.Microscopically,in all rabbits of low activity and high activity groups,there were membrana mucosa necrotic and swell and breakage of the muscle fiber in esophageal submucosa and muscularis,submucosal inflammation,which were more severe in high activity group.In low activity group,one esophagus ectal membrane was involved,however,esophageal perforation did not develop.In high activity group,3 of 6rabbits esophageal perforation had developed,in which one esophagus mediastinum fistula developed,without inflammation.In non-radioactive group,it was almost normal in mucosa layer,a small amount of inflammatory cells were found in submucosal layer,and part of muscle fibers was fractured and no pathological changes of necrosis was found.Conclusions Radioactive 125I carbon nanotubes covered metallic stent with low activity(3.7 -5.6 MBq) can be used as intraluminal palliative brachytherapy,which is safe and effective.

Comparative venom gland transcriptome analysis of the scorpion Lychas mucronatus reveals intraspecific toxic gene diversity and new venomous components.

BACKGROUND: Lychas mucronatus is one scorpion species widely distributed in Southeast Asia and southern China. Anything is hardly known about its venom components, despite the fact that it can often cause human accidents. In this work, we performed a venomous gland transcriptome analysis by constructing and screening the venom gland cDNA library of the scorpion Lychas mucronatus from Yunnan province and compared it with the previous results of Hainan-sourced Lychas mucronatus. RESULTS: A total of sixteen known types of venom peptides and proteins are obtained from the venom gland cDNA library of Yunnan-sourced Lychas mucronatus, which greatly increase the number of currently reported scorpion venom peptides. Interestingly, we also identified nineteen atypical types of venom molecules seldom reported in scorpion species. Surprisingly, the comparative transcriptome analysis of Yunnan-sourced Lychas mucronatus and Hainan-sourced Lychas mucronatus indicated that enormous diversity and vastly abundant difference could be found in venom peptides and proteins between populations of the scorpion Lychas mucronatus from different geographical regions. CONCLUSIONS: This work characterizes a large number of venom molecules never identified in scorpion species. This result provides a comparative analysis of venom transcriptomes of the scorpion Lychas mucronatus from different geographical regions, which thoroughly reveals the fact that the venom peptides and proteins of the same scorpion species from different geographical regions are highly diversified and scorpion evolves to adapt a new environment by altering the primary structure and abundance of venom peptides and proteins.

Characterization of a new Kv1.3 channel-specific blocker, J123, from the scorpion Buthus martensii Karsch.

The potassium channel Kv1.3 is an attractive pharmacological target for T-cell-mediated autoimmune diseases, and specific and selective peptidic blockers of Kv1.3 channels have served as valuable therapeutic leads for treating these diseases. Here, we found a new peptide toxin, J123, with 43 amino acids including six cysteine residues by screening the venomous cDNA library of scorpion Buthus martensii Karsch, which has been used as traditional medicine in China for more than 2000 years. The sequence analysis suggested that peptide J123 constituted a new member of the alpha-KTx toxins. The electrophysiological experiments further indicated that peptide J123 has a novel pharmacological profiles: it blocked Kv1.3 channel with high potency (IC50=0.79 nM), and exhibited good selectivity on Kv1.3 over Kv1.1 (>1000-fold) and Kv1.2 (about 30-fold), respectively. Furthermore, peptide J123 had no activity on SKCa2 and SKCa3 channels at micromolar concentration level. Based on the pharmacological activities, the possible channel-interacting surface of peptide J123 was also predicted by molecular modeling and docking. All these data not only enrich the knowledge of the structure-function relationship of the new Kv1.3-speicific peptide but also present a potential drug candidate for selectively targeting Kv1.3 channels.

Co-expression and synergic effect of human complement regulatory proteins DAF and MCP / 生物工程学报

Recombinant expression vector pcDNA3-DAFMCP-DP containing human membrane complement regulatory proteins (hCRPs) decay accelerating factor (DAF) and membrane cofactor protein (MCP) cDNA was constructed by using two independent promoters. After transfected into NIH3T3 cells by calcium phosphate-DNA precipitate method, NIH3T3 pcDNA3-DAFMCP-DP transfectants were obtained by G418 selection. Extraneous genes integration was identified by PCR. The co-expression of human DAF and MCP at both mRNA and protein levels was confirmed by using RT-PCR and Western blot analysis. Human DAF and MCP cDNA were integrated into NIH3T3 pcDNA3-DAFMCP-DP genomic DNA after continuous 30 times passages, indicating that NIH3T3 pcDNA3-DAFMCP-DP were stable cell lines. Human C-mediated cytolysis assays showed that NIH3T3 cells transfected stably with pcDNA3-DAF, pcDNA3-MCP, and pcDNA3-DAFMCP-DP were protected from C-mediated damage and co-expressed human DAF and MCP provided more excellent protection against C-mediated attack, which was compared with either DAF or MCP alone. These results suggest that the dicistronic vector could improve the efficiency of multi-gene delivery and benefit the synergic effect of human membrane complement regulatory proteins DAF and MCP.

Conformation of trimeric envelope glycoproteins: the CD4-dependent membrane fusion mechanism of HIV-1.

The HIV-1 envelope glycoproteins are assembled by the trimeric gp120s and gp41s proteins. The gp120 binds sequentially to CD4 and coreceptor for initiating virus entry. Because of noncovalent interaction and heavy glycosylation for envelope glycoproteins, it is highly difficult to determine entire envelope glycoproteins structure now. Such question extremely limits our good understanding of HIV-1 membrane fusion mechanism. Here, a novel and reasonable assembly model of trimeric gp120s and gp41s was proposed based on the conformational dynamics of trimeric gp120-gp41 complex and gp41, respectively. As for gp41, the heptad repeat sequences in the gp41 C-terminal is of enormous flexibility. On the contrary, the heptad repeat sequences in the gp41 N-terminal likely present stable three-helical bundle due to strong nonpolar interaction, and they were predicted to associate three alpha1 helixes from the non-neutralizing face of the gp120 inner domain, which is quite similar to gp41 fusion core structure. Such interaction likely leads to the formation of noncovalent gp120-gp41 complex. In the proposed assembly of trimeric gp120-gp41 complex, three gp120s present not only perfectly complementary and symmetrical distribution around the gp41, but also different flexibility degree in the different structural domains. Thus, the new model can well explain numerous experimental phenomena, present plenty of structural information, elucidate effectively HIV-1 membrane fusion mechanism, and direct to further develop vaccine and novel fusion inhibitors.

The effect of intron location on the splicing of BmKK2 in 293T cells.

Previously reported results showed that the BmKK2's intron could be recognized and spliced in cultured HEK 293T cells. At the same time, a cryptic splicing site of BmKK2 gene was found in the second exon. Moreover, replacing BmKK2's intron with BmP03's intron (an artificial BmKK2-BmP03 mosaic gene) did not affect the intron's recognition and splicing, but increased the expression level of the toxin-GFP fusion protein (Cao et al., J Biochem Mol Toxicol 2006;20:1-6). In this investigation, the BmKK2's intron with 79 nucleotides length was artificially shifted from the 49th nt (the 17th Gly codon between the first base and the second base) to the 100th nt (the 34th Gly codon between the first base and the second base). Based on the constructed intron-splicing system, the results of RT-PCR and the western blotting analysis showed that the BmKK2's shifted-intron (named BmKK2-s) was not recognized and spliced correctly, but the cryptic splicing site of BmKK2 gene was still spliced in the second exon, which possibly indicated that locations of introns were very important to the recognition and splicing of introns, and splicing of introns was very much associated with the corresponding upstream and downstream exons. This result possibly provides evidence for splice-site recognition across the exons.

Splicing of scorpion toxin gene BmKK2 in HEK 293T cells.

Using GFP as a reporter gene, splicing of scorpion toxin gene BmKK2 was investigated in cultured HEK 293T cells. The results of RT-PCR and western blotting showed that BmKK2's intron could be recognized and spliced in cultured HEK 293T cells. At the same time, a cryptic splicing site of BmKK2 gene was found at the 91st nucleotide site of the second exon, which is a typical form of alternative splicing. For the first time, alternative splicing would partially explain the diversity of scorpion toxins at the gene level. Moreover, replacing BmKK2's intron with BmP03's intron (an artificial BmKK2-BmP03 mosaic gene) did not affect the intron's recognition and splicing, but increased the expression of the toxin-GFP fusion protein by fluorescence imaging, which indicated that both introns may regulate the expression of toxin-GFP fusion protein. The artificial BmKK2-BmP03 mosaic gene was also spliced into two kinds of mRNA molecules, which showed that sequence of intron was not absolutely conserved. The results suggested that introns of scorpion toxin genes BmKK2 and BmP03 increase the diversity of scorpion toxins and regulate the expression of their genes.

Genetic mechanisms of scorpion venom peptide diversification.

The diversity of scorpion venom peptides is well shown by the presence of about 400 such polypeptides with or without disulfide bonds. Scorpion toxins with disulfide bonds present a variety of sequence features and pharmacological functions by affecting different ion channels, while the venom peptides without disulfide bonds represent a new subfamily, having much lower sequence homology among each other and different functions (e.g. bradykinin-potentiating, antimicrobial, molecular cell signal initiating and immune modulating). Interestingly, all scorpion venom peptides with divergent functions may have evolved from a common ancestor gene. Over the lengthy evolutionary time, the diversification of scorpion venom peptides evolved through polymorphism, duplication, trans-splicing, or alternative splicing at the gene level. In order to completely clarify the diversity of scorpion toxins and toxin-like peptides, toxinomics (genomics and proteomics of scorpion toxins and toxin-like peptides) are expected to greatly advance in the near future.

Cloning and characterization of a novel calcium channel toxin-like gene BmCa1 from Chinese scorpion Mesobuthus martensii Karsch.

Many studies have been carried on peptides and genes encoding scorpion toxins from the venom of Mesobuthus martensii Karsch (synonym: Buthus martensii Karsch, BmK), such as Na+, K+ and Cl- channel modulators. In this study, a novel calcium channel toxin-like gene BmCa1 was isolated and characterized from the venom of Mesobuthus martensii Karsch. First, a partial cDNA sequence of the Ca2+ channel toxin-like gene was identified by random sequencing method from a venomous gland cDNA library of Mesobuthus martensii Karsch. The full-length sequence of BmCa1 was then obtained by 5'RACE technique. The peptide deduced from BmCa1 precursor nucleotide sequence contains a 27-residue signal peptide and a 37-residue mature peptide. Although BmCa1 and other scorpion toxins are different at the gene and protein primary structure levels, BmCa1 has the same precursor nucleotide organization and cysteine arrangement as that of the first subfamily members of calcium channel scorpion toxins. Genomic DNA sequence of BmCa1 was also cloned by PCR. Sequence analysis showed that BmCa1 gene consists of three exons separated by two introns of 72 bp and 1076 bp in length, respectively. BmCa1 is the first calcium channel toxin-like gene cloned from the venom of Mesobuthus martensii Karsch and potentially represents a novel class of calcium channel toxins in scorpion venoms.