Identification and characterization of GH receptor and serum GH-binding protein in Chinese sturgeon (Acipenser sinensis).

Chinese sturgeon, a kind of cartilage ganoid, has a history of over one billion years and it is called the living fossil of aquatic biology since it keeps some evolutionary trace. Here, we characterized the growth hormone receptor (GHR) and serum growth hormone binding protein (GHBP) of Chinese sturgeon. It was shown that GHR was expressed in various tissues, mainly in hepatic, kidney and intestine tissues.

Functional expression of guinea pig growth hormone receptor and its mutants in mammalian cells.

The cDNA of guinea pig (Cavia porcellus) growth hormone receptor (gpGHR) was cloned using RT-PCR in our laboratory. By sequence alignment, substitutions of amino acids conserved in other mammalian GHRs were found. For example, histidine-168 and tyrosine-332 equivalent to positions 170 and 333 in other mammalian GHRs, which were considered to be necessary for the dimerization of GHR and the specific GH-stimulated functions respectively, were replaced by tyrosine and serine in gpGHR.

[Secretory Expression of the Superactive [Lys(17,18),Glu(21)]-Glucagon in E. coli].

One of the most important findings in structure-function studies on glucagon by means of chemical synthesis is the discovery that [Lys(17,18),Glu(21)]-glucagon had higher biological activity than native glucagon. This mutant of glucagon was called superactive glucagon (SA-glucagon). In the present work, the possibility to obtain SA-glucagon by means of genetic engineering was studied.

Preparation and Biological Activity of [B(1)Ala, B(2)Ala, B(3)Lys]-Insulin.

This paper describes the preparation and biological activity of an insulin analogue in which the B1-3 sequence (Phe-Val-Asn) of insulin is substituted by Ala-Ala-Lys. [B(1)Ala, B(2)Ala, B(3)Lys]-Insulin retains full in vivo activity and receptor binding activity as insulin, but its lipogenesis activity and immunoactivity are 70 % and 0.88 % of those of insulin respectively.

cDNA Cloning of the Cytoplasmic Domain of Growth Hormone Receptor from guinea Pig and Homology Comparison.

The evolutionary position of guinea pig has not been unequivocally clarified, and it appears to show abnormalities in GH response. The cDNA of GHR cytoplasmic domain from guinea pig was cloned and sequenced. By homology comparison, it was found that the sequence we obtained was different markedly from that of rat or mouse.

cDNA Cloning of the Guinea Pig Growth Hormone Receptor.

cDNA cloning and 1 899 bp sequence of growth hormone receptor (GHR) from guinea pig liver are described. The guinea pig GHR consists of 610 amino acids. The structural feature and homology comparison of guinea pig GHR are also reported.

Effects of Divalent Cations and Disulfide Bond Reducing Agents on Specific Binding of Growth Hormone to Liver Membrane Receptors from Snakehead Fish (Ophiocephalus argus, Cantor).

Divalent cations, Ca(2 ), Mg(2 ) and Mn(2 ) enhance the binding of bream growth hormone (brGH) to snakehead fish liver membrane, and their optimum concentration was found to be 8 12 mmol/L, at which Ca(2 ), Mg(2 ) and Mn(2 ) could increase, respectively, the specific binding to 230%, 180%, and 200%, compared with the binding in the absence of ions. The Eadie-Scatchard plot was used for the dynamic analysis of the Ca(2 ) binding site. A low affinity Ca(2 ) binding site was found in the GH-receptor complex with K(m)=0.

The Receptor Binding and Biological Activity of [B1-Ala, B2-Ala]-insulin.

The receptor binding properties with human placental membrane (HPM) and the in vitro biological activity of an insulin analogue, [B1-Ala, B2-Ala]-insulin were investigated in detail and compared with those of insulin. It was found that the binding of (125)I-[B1-Ala, B2-Ala]-insulin and (125)I-insulin to HPM was time dependent reaching equilibrium after 6min at 37 degrees in the presence of bacitracin with an equilibrium maximum binding of 6.44 fmol/mg protein for [B1-Ala, B2-Ala]-insulin and 3.

Protein Engineering of Insulin: [B9 Glutamic Acid] Human Insulin.

B9Ser of insulin B chain was substituted by Glu using site-directed mutagenesis to obtain a fast-acting insulin-[B9Glu] human insulin. The receptor binding capacity and in vivo biological activity of [B9Glu] human insulin are 21% and 40% as those of porcine insulin respectively.