The abzyme with deiodinase activity was modified with diethyl pyrocarbonate(DEPC) and carbodiimide(EDC) respectively. The modified abzymes were dialyzed and their activities were compared with that of the native abzym...The abzyme with deiodinase activity was modified with diethyl pyrocarbonate(DEPC) and carbodiimide(EDC) respectively. The modified abzymes were dialyzed and their activities were compared with that of the native abzyme. The results indicate that the histidine residue is one of the essential groups in the abzyme, and the modification causes the catalytic activity a loss of 70%. The modification of the residues containing carboxyl group with EDC leads to a loss of 50% activity, indicating that acid amino residues play important roles in the catalytic reaction.展开更多
Three thyroxine haptens were synthesized by protecting amino group of thyroxine with Cu 2+ ion and characterized by 1H NMR, MS, elemental analysis and IR. Thyroxine and the derivatives were coupled with carrier protei...Three thyroxine haptens were synthesized by protecting amino group of thyroxine with Cu 2+ ion and characterized by 1H NMR, MS, elemental analysis and IR. Thyroxine and the derivatives were coupled with carrier proteins(BSA and Ovalbumin). Thus antigens were prepared and hapten quantities of the antigens were measured by UV spectroscopy at 320 nm. An anti O methyl T 4 monoclonal antibody was prepared by immunization, cell fusion and screening.展开更多
Iodothyronine deiodinase catalyzes the initiation and termination of thyroid hormones(THs) effects, and plays a central role in the regulation of thyroid hormone level in vertebrates. In non-chordate invertebrates, on...Iodothyronine deiodinase catalyzes the initiation and termination of thyroid hormones(THs) effects, and plays a central role in the regulation of thyroid hormone level in vertebrates. In non-chordate invertebrates, only one deiodinase has been identified in the scallop C hlamys farreri. Here, two deiodinases were cloned in the Pacific oyster C rassostrea gigas( Cg Dx and C g Dy). The characteristic in-frame TGA codons and selenocysteine insertion sequence elements in the oyster deiodinase c DNAs supported the activity of them. Furthermore, seven orthologs of deiodinases were found by a tblastn search in the mollusk Lottia gigantea and the annelid C apitella teleta. A phylogenetic analysis revealed that the deiodinase gene originated from an common ancestor and a clade-specific gene duplication occurred independently during the differentiation of the mollusk, annelid, and vertebrate lineages. The distinct spatiotemporal expression patterns implied functional divergence of the two deiodinases. The expression of C g Dx and Cg Dy was influenced by L-thyroxine T4, and putative thyroid hormone responsive elements were found in their promoters, which suggested that the oyster deiodinases were feedback regulated by TH. Epinephrine stimulated the expression level of C g Dx and Cg Dy, suggesting an interaction effect between different hormones. This study provides the first evidence for the existence of a conserved TH feedback regulation mechanism in mollusks, providing insights into TH evolution.展开更多
文摘The abzyme with deiodinase activity was modified with diethyl pyrocarbonate(DEPC) and carbodiimide(EDC) respectively. The modified abzymes were dialyzed and their activities were compared with that of the native abzyme. The results indicate that the histidine residue is one of the essential groups in the abzyme, and the modification causes the catalytic activity a loss of 70%. The modification of the residues containing carboxyl group with EDC leads to a loss of 50% activity, indicating that acid amino residues play important roles in the catalytic reaction.
文摘Three thyroxine haptens were synthesized by protecting amino group of thyroxine with Cu 2+ ion and characterized by 1H NMR, MS, elemental analysis and IR. Thyroxine and the derivatives were coupled with carrier proteins(BSA and Ovalbumin). Thus antigens were prepared and hapten quantities of the antigens were measured by UV spectroscopy at 320 nm. An anti O methyl T 4 monoclonal antibody was prepared by immunization, cell fusion and screening.
基金Supported by the National Natural Science Foundation of China(Nos.31372515,31402285)the National Basic Research Program of China(973 Program)(No.2010CB126401)the National High Technology Research and Development Program(863 Program)(No.2012AA10A405)
文摘Iodothyronine deiodinase catalyzes the initiation and termination of thyroid hormones(THs) effects, and plays a central role in the regulation of thyroid hormone level in vertebrates. In non-chordate invertebrates, only one deiodinase has been identified in the scallop C hlamys farreri. Here, two deiodinases were cloned in the Pacific oyster C rassostrea gigas( Cg Dx and C g Dy). The characteristic in-frame TGA codons and selenocysteine insertion sequence elements in the oyster deiodinase c DNAs supported the activity of them. Furthermore, seven orthologs of deiodinases were found by a tblastn search in the mollusk Lottia gigantea and the annelid C apitella teleta. A phylogenetic analysis revealed that the deiodinase gene originated from an common ancestor and a clade-specific gene duplication occurred independently during the differentiation of the mollusk, annelid, and vertebrate lineages. The distinct spatiotemporal expression patterns implied functional divergence of the two deiodinases. The expression of C g Dx and Cg Dy was influenced by L-thyroxine T4, and putative thyroid hormone responsive elements were found in their promoters, which suggested that the oyster deiodinases were feedback regulated by TH. Epinephrine stimulated the expression level of C g Dx and Cg Dy, suggesting an interaction effect between different hormones. This study provides the first evidence for the existence of a conserved TH feedback regulation mechanism in mollusks, providing insights into TH evolution.
