The electrochemical behavior of mixed Langmuir-Blodgett (LB) film of bilir ubin and phosphatidyl ethanolamine on glassy carbon electrode were investigated with cyclic voltammetry and differential pulse voltammetry. Th...The electrochemical behavior of mixed Langmuir-Blodgett (LB) film of bilir ubin and phosphatidyl ethanolamine on glassy carbon electrode were investigated with cyclic voltammetry and differential pulse voltammetry. The results prove th at bilirubin Langmuir-Blodgett film has a cathodic peak of +420mV in 0.2mol ·L-1 HAc-NaAc-50%EtOH(pH=5.4) solution. The peak current increases wit h the layer number of bilirubin LB film in the range of 1 to 12 layers. The resu t of the electrochemical behavior of bilirubin in ordered LB film was also compa red with that in cast film and in aqueous solution at glassy carbon electrode. W e found that bilirubin has the similar electrochemical behavior in LB film to in cast film, but different from that in aqueous solution.展开更多
As a group of intestinal hormones and neurotransmitters, cholecystokinins（CCKs） regulate and affect pancreatic enzyme secretion, gastrointestinal motility, pain hypersensitivity, digestion and satiety, and generally...As a group of intestinal hormones and neurotransmitters, cholecystokinins（CCKs） regulate and affect pancreatic enzyme secretion, gastrointestinal motility, pain hypersensitivity, digestion and satiety, and generally contain a DYMGWMDFG sequence at the C-terminus. Many CCKs have been reported in mammals. However, only a few have been reported in amphibians, such as Hyla nigrovittata, Xenopus laevis, and Rana catesbeiana, with none reported in urodele amphibians like newts and salamanders. Here, a CCK called CCK-TV was identified and characterized from the skin of the salamander Tylototriton verrucosus. This CCK contained an amino acid sequence of DYMGWMDF-NH2 as seen in other CCKs. A c DNA encoding the CCK precursor containing 129 amino acid residues was cloned from the c DNA library of T. verrucosus skin. The CCK-TV had the potential to induce the contraction of smooth muscle strips isolated from porcine gallbladder, eliciting contraction at a concentration of 5.0x10-11 mol/L and inducing maximal contraction at a concentration of 2.0x10-6 mol/L. The EC50 was 13.6 nmol/L. To the best of our knowledge, this is the first report to identify the presence of a CCK in an urodele amphibian.展开更多
文摘The electrochemical behavior of mixed Langmuir-Blodgett (LB) film of bilir ubin and phosphatidyl ethanolamine on glassy carbon electrode were investigated with cyclic voltammetry and differential pulse voltammetry. The results prove th at bilirubin Langmuir-Blodgett film has a cathodic peak of +420mV in 0.2mol ·L-1 HAc-NaAc-50%EtOH(pH=5.4) solution. The peak current increases wit h the layer number of bilirubin LB film in the range of 1 to 12 layers. The resu t of the electrochemical behavior of bilirubin in ordered LB film was also compa red with that in cast film and in aqueous solution at glassy carbon electrode. W e found that bilirubin has the similar electrochemical behavior in LB film to in cast film, but different from that in aqueous solution.
基金supported by the National Basic Research Program of China（973 Program）（2013CB911300）National Natural Science Foundation of China（U1132601）the Chinese Academy of Sciences（SAJC201308）
文摘As a group of intestinal hormones and neurotransmitters, cholecystokinins（CCKs） regulate and affect pancreatic enzyme secretion, gastrointestinal motility, pain hypersensitivity, digestion and satiety, and generally contain a DYMGWMDFG sequence at the C-terminus. Many CCKs have been reported in mammals. However, only a few have been reported in amphibians, such as Hyla nigrovittata, Xenopus laevis, and Rana catesbeiana, with none reported in urodele amphibians like newts and salamanders. Here, a CCK called CCK-TV was identified and characterized from the skin of the salamander Tylototriton verrucosus. This CCK contained an amino acid sequence of DYMGWMDF-NH2 as seen in other CCKs. A c DNA encoding the CCK precursor containing 129 amino acid residues was cloned from the c DNA library of T. verrucosus skin. The CCK-TV had the potential to induce the contraction of smooth muscle strips isolated from porcine gallbladder, eliciting contraction at a concentration of 5.0x10-11 mol/L and inducing maximal contraction at a concentration of 2.0x10-6 mol/L. The EC50 was 13.6 nmol/L. To the best of our knowledge, this is the first report to identify the presence of a CCK in an urodele amphibian.
