Sensitivity of hybrid ovine/rat GH receptors to oGH and rat GH in transfected FDC-P1 mouse myeloid cells in vitro

Association study between growth hormone receptor (GHR ) gene polymorphisms and obesity in Korean population

A main target of growth hormone (GH) is adipose tissue in human body. The GH secretion in obesity patients is impaired. It is needless to say that growth hormone receptor (GHR) is necessary in GH hormone signaling. The purpose of the present study is to examine the association between single nucleotide polymorphisms (SNPs) and the development of obesity. A total of 211 overweight/obese subjects with a body mass index (BMI) ≥23 kg/m² and 157 nonoverweight/obese controls with a BMI of 18.5–23.0 kg/m² were involved in this study. Seven SNPs including the rs6451620 (intron), rs4130114 (intron), rs4410646 (intron), rs6898743 (intron), rs4394131 (intron), rs6182 (Cys440Phe), and rs6184 (Pro579Thr) and rs2229765 SNPs of GHR gene were genotyped. Genotyping was performed using custom DNA chip. SNPStats was used to calculate the odds ratio, 95% confidence interval, and P-value. The link-age disequilibrium block and haplotypes among seven SNPs were determined using Haploview version 4.2. Dominant, recessive, and log-additive genetic models were conducted for genetic analyzing. Among tested SNPs in GHR gene, rs4410646 and rs6898743 showed significant association with obesity (rs4410646, P=0.02 in dominant model and P=0.036 in log-additive model; rs6898743, P=0.039 in dominant model and P=0.044 in log-additive model). In summary, these results suggest that GHR gene polymorphisms might play a role in the development of obesity in the Korean population.

Mink growth hormone structural-functional relationships: effects of renaturing and storage conditions

Fourier-transform infrared spectroscopy, in vitro bioassay and enzyme-linked immunoassay were used to study the structural-functional relationships of recombinant mink growth hormone (mGH), refolded and stored under different conditions. Porcine GH (pGH) was synthesized and used as an example. These two hormones, when refolded and stored the same way, had the same secondary structures, biological and immunological efficacy, and biological potency. Only the immunological potency differed, mGH being significantly less potent than pGH. Renaturation pH and storing frozen or at 4 degrees C in 5% glycerol did not affect either the secondary structure or the activity. However, freeze-drying raised the content of buried alpha-helices and lowered that of solvated alpha-helices and of unordered structures. These conformational changes were associated with a reduction of immunological and biological potency of mGH and of immunological potency of pGH. These findings provide original information on the secondary structure of mGH, and show that conformational changes induced by lyophilization adversely affect its activity.