Deletion of amino acid residues 33-46 in growth hormone alters the hydrophobicity of the molecule

Growth hormone (GH) variants have been studied for the structure-function relationship of the molecule. The presence of a potential alternate splicing point in mRNA in bGH gene at exon 3, similar to hGH has been reported by workers. Early investigation on the characteristics of the chemistry of 20koGH showed that the molecule was produced by site-directed mutagenesis by deleting amino acid residues 33-46 and the resultant DNA was expressed in E. coli under the control of lac promoter in pUC based plasmid. The mutant protein remained insoluble and did not refold. To investigate the effect of deletion on the chemistry of the molecule, computational biology tools were employed. The mutant with the deletion of amino acid residues 33-46, was designed and the model was visualized on computer. The structure of 20k bGH was compared with bGH and dissected for hydrogen bonds and hydrophobicity. Computational biology tools were helpful in elucidating the role of 33-46 amino acid residuesdomain in the chemistry of the molecule. Furthermore, it was revealed that removal of amino acid residues 33-46 which formed the hydrogen bonds involving Glu 33, Gln 46, Pro 38, Arg 42, Tyr 43,Ala 51, Thr 48, Asn 47, led to the formation of new hydrogen bonds between Thr 33, Tyr 144, Asn 32, Asn 32 and Ser and Asp 153. The removal of the amino acids 33-46 decreased the hydro-phobicity of the first helix of bGH molecule, as compared to 20k hGH, thus altering the solubility of the molecule, confirming the earlier reported results for ovine growth hormone with same deletion

Production, purification and characterization of two recombinant DNA-derived N-terminal ovine growth hormone variants: oGH3 and oGH5

Two recombinant DNA-derived variants of ovine growth hormone were produced, purified, characterized and compared with the authentic pituitary derived GH. The variants oGH3 and oGH5 were isolated by differential centrifugation method and were purified after refolding by ion-exchangechromatography and gel filtration. Both the proteins showed single band on SDS-PAGE and had molecular weight and iso-electric point closer to authentic pituitary GH. The variants oGH3 and oGH5 were compared with the authentic pituitary derived GH in radio immuno assays, radio receptor assays and binding with the monoclonal antibodies OA 11 and OA12

Gene study within the 5' flanking regions of growth hormone gene of first exon in Bos indicus

Growth hormone (GH) is a main regulatory protein secreted by pituitary gland and placenta, involved in most anabolic processes in mammals. Expression of more than one gene for GH has been reported, indicating polymorphism at gene and protein level; apart from this, silent mutations has also been reported, relating to the level of expression of GH gene. The aim of this study is to identify silent mutations within the 5' flanking regions of GH2 gene of the first exon in Bos indicus. DNA was isolatedfrom the blood of freshly slaughtered animal and a set of primer was used for gene amplification, binding at 5' flanking region of GH gene at chromosome 19. DNA was amplified and the resultant product of about 453 bp was sequenced. The results showed that there were 9 changes including 8 replacements and one addition, for GH 2.3 allele, as compared to Bos taurus Genome (Btau_4.0 ) and two earlier reported alleles 2.1 and 2.2 for GH2 gene in B indicus. As this region is related to higher milk production, growth regulation, carcass and immune response traits in livestock, these changes could be used as a genetic marker. The reported sequence has been deposited to the European Molecular Biology Laboratory (EMBL) with the Accession Number FN666263.Key words: Bos indicus, growth hormone gene, silent mutation, growth hormone (GH) gene, allele

Isolation of cellulolytic activities from Tribolium castaneum (red flour beetle)

Cellulolytic enzymes have immense potential to convert cellulosic biomass into useful products. Tribolium castaneum crude proteins were isolated to screen the cellulolytic activities. The activity was established by substrate-agar plate assay and confirmed by endoglucanase assay. Cellulolytic activitywas further purified and characterized using the different chromatographic techniques and electrophoresis. Gel filtration chromatography showed the presence of multiple forms of enzyme activities with different molecular weights. Stability of enzyme activity was investigated at differenttemperatures and pH. Optimum pH for was found 4.8 at 40oC determined as optimum temperature. Gradually decreasing Enzyme activity remained half at 60oC. Zymography and SDS-PAGE showed the presence of multiple forms of endoglucanase activities (Cel I and Cel II) with molecular weight of 55 kDaand 35 kDa

Radiofrequency ablation for Barrett's oesophagus related neoplasia with the 360 Express catheter: initial experience from the United Kingdom and Ireland—preliminary results

BACKGROUND: Radio-frequency ablation (RFA) for Barrett's oesophagus (BE)-related neoplasia is currently used after endoscopic resection of visible neoplasia. The HALO 360 balloon has been used to ablate long segment BE. The Barrx™ 360 Express RFA self-sizing catheter ('RFA Express') may potentially allow quicker ablation times and improved treatment outcomes. The aim of this paper is to present real world data on the use of the 360 Express Device. METHODS: Centres in the UK and Ireland submitted cases where the RFA Express was used. The primary outcome was regression of BE at 3 months. Secondary outcomes were the rate of symptomatic stricture formation and resolution of intestinal metaplasia (CR-IM) and dysplasia (CR-D) at End of Treatment (EoT). RESULTS: 11 centres submitted 123 consecutive patients. 112 had a follow up endoscopy. The median age was 67 years (IQR 62-75). 3 dosimetries were used. The mean reduction in Circumferential (C) length was 78% ± 36 and mean reduction in Maximal length (M) was 55% ± 36. 17 patients (15%) developed strictures requiring dilation. There was a higher rate of stricture formation when the 12 J energy was used (p < 0.05). 47 patients had EoT biopsies, 40 (85%) had CR-D and 34(76%) had CR-IM. CONCLUSIONS: The RFA 360 Express catheter shows reduction in length of baseline BE at 3 months after index treatment, and eradication of intestinal metaplasia and dysplasia at 12 months similar to other studies with earlier devices. It appears that the symptomatic stricture rate is slightly higher than previous series with the HALO 360 catheter. This study was performed as part of the HALO registry and has been approved by the Research Ethics Committee - MREC Number 08/H0714/27 Local project reference 08/0104 Project ID 15,033 IRAS Number 54678 EudraCT 2009-015980-1. Registered on ISRCTN as below: ISRCTN93069556. https://doi.org/10.1186/ISRCTN93069556

Coronary artery bypass surgery in high-risk patients

BACKGROUND: In high-risk coronary artery bypass patients; off-pump versus on-pump surgical strategies still remain a matter of debate, regarding which method results in a lower incidence of perioperative mortality and morbidity. We describe our experience in the treatment of high-risk coronary artery patients and compare patients assigned to on-pump and off-pump surgery. METHODS: From March 2002 to July 2004, 86 patients with EuroSCOREs > 5 underwent myocardial revascularization with or without cardiopulmonary bypass. Patients were assigned to off-pump surgery (40) or on-pump surgery (46) based on coronary anatomy coupled with the likelihood of achieving complete revascularization. RESULTS: Those patients undergoing off-pump surgery had significantly poorer left ventricular function than those undergoing on-pump surgery (28.6 ± 5.8% vs. 40.5 ± 7.4%, respectively, p < 0.05) and also had higher Euroscore values (7.26 ± 1.4 vs. 12.1 ± 1.8, respectively, p < 0.05). Differences between the two groups were nonsignificant with regard to number of grafts per patient, mean duration of surgery, anesthesia and operating room time, length of stay intensive care unit (ICU) and rate of postoperative atrial fibrillation CONCLUSION: Utilization of off-pump coronary artery bypass graft (CABG) does not confer significant clinical advantages in all high-risk patients. This review suggest that off-pump coronary revascularization may represent an alternative approach for treatment of patients with Euroscore ≥ 10 and left ventricular function ≤ 30%

Predicting Peptide Binding Affinities to MHC Molecules Using a Modified Semi-Empirical Scoring Function

The Major Histocompatibility Complex (MHC) plays an important role in the human immune system. The MHC is involved in the antigen presentation system assisting T cells to identify foreign or pathogenic proteins. However, an MHC molecule binding a self-peptide may incorrectly trigger an immune response and cause an autoimmune disease, such as multiple sclerosis. Understanding the molecular mechanism of this process will greatly assist in determining the aetiology of various diseases and in the design of effective drugs. In the present study, we have used the Fresno semi-empirical scoring function and modify the approach to the prediction of peptide-MHC binding by using open-source and public domain software. We apply the method to HLA class II alleles DR15, DR1, and DR4, and the HLA class I allele HLA A2. Our analysis shows that using a large set of binding data and multiple crystal structures improves the predictive capability of the method. The performance of the method is also shown to be correlated to the structural similarity of the crystal structures used. We have exposed some of the obstacles faced by structure-based prediction methods and proposed possible solutions to those obstacles. It is envisaged that these obstacles need to be addressed before the performance of structure-based methods can be on par with the sequence-based methods

f(R) theories

Over the past decade, f(R) theories have been extensively studied as one of the simplest modifications to General Relativity. In this article we review various applications of f(R) theories to cosmology and gravity - such as inflation, dark energy, local gravity constraints, cosmological perturbations, and spherically symmetric solutions in weak and strong gravitational backgrounds. We present a number of ways to distinguish those theories from General Relativity observationally and experimentally. We also discuss the extension to other modified gravity theories such as Brans-Dicke theory and Gauss-Bonnet gravity, and address models that can satisfy both cosmological and local gravity constraints.Comment: 156 pages, 14 figures, Invited review article in Living Reviews in Relativity, Published version, Comments are welcom