Sex-dimorphic moderate hypoglycemia preconditioning effects on Hippocampal CA1 neuron bio-energetic and anti-oxidant function

Molecular and Cellular Biochemistry - Hypoglycemia is a detrimental complication of rigorous management of type 1 diabetes mellitus. Moderate hypoglycemia (MH) preconditioning of male rats...     

Management of chronic hepatitis C: clinical audit of biopsy based management algorithm.

OBJECTIVE: To assess the attendance, outcome, compliance with treatment, and response to interferon alfa in patients with chronic hepatitis C who attended during 1995 and were treated according to a biopsy based algorithm. DESIGN: Retrospective audit of all patients with chronic hepatitis C attending outpatient clinics over one year. SETTING: The liver unit at a London teaching hospital. SUBJECTS: 255 patients with chronic hepatitis C. MAIN OUTCOME MEASURES: Patient survival, attendance, and compliance with diagnostic and therapeutic regimens. Response to interferon alfa treatment, based on loss of viraemia three months after cessation of treatment. RESULTS: A large proportion of patients (39%) with newly diagnosed chronic hepatitis C infection do not want to undergo further investigation. Of those patients who do attend for further treatment, a large proportion with severe hepatic fibrosis (42%) do not want to undergo currently available treatment. The response rate to interferon (21%) in treated patients was similar to that previously reported in a trial setting. There was no significant difference in response rates in patients with or without severe fibrosis not amounting to cirrhosis. In patients with cirrhosis there was a high incidence of hepatocellular carcinoma (18%) over a follow up period of 20 months. CONCLUSION: Current strategies aimed at investigating and treating patients with chronic hepatitis C are not acceptable to a large proportion of patients. Many patients with cirrhosis related to hepatitis C infection develop hepatic neoplasms, and management strategies to deal with this problem are urgently required.     

Scalable Geometrically Designed Protein Cages Assembled via Genetically Encoded Split Inteins

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Modulation of the multistate folding of designed TPR proteins through intrinsic and extrinsic factors

Tetratricopeptide repeats (TPRs) are a class of all alpha-helical repeat proteins that are comprised of 34-aa helix-turn-helix motifs. These stack together to form nonglobular structures that are stabilized by short-range interactions from residues close in primary sequence. Unlike globular proteins, they have few, if any, long-range nonlocal stabilizing interactions. Several studies on designed TPR proteins have shown that this modular structure is reflected in their folding, that is, modular multistate folding is observed as opposed to two-state folding. Here we show that TPR multistate folding can be suppressed to approximate two-state folding through modulation of intrinsic stability or extrinsic environmental variables. This modulation was investigated by comparing the thermodynamic unfolding under differing buffer regimes of two distinct series of consensus-designed TPR proteins, which possess different intrinsic stabilities. A total of nine proteins of differing sizes and differing consensus TPR motifs were each thermally and chemically denatured and their unfolding monitored using differential scanning calorimetry (DSC) and CD/fluorescence, respectively. Analyses of both the DSC and chemical denaturation data show that reducing the total stability of each protein and repeat units leads to observable two-state unfolding. These data highlight the intimate link between global and intrinsic repeat stability that governs whether folding proceeds by an observably two-state mechanism, or whether partial unfolding yields stable intermediate structures which retain sufficient stability to be populated at equilibrium.     

Protein denaturation and protein:drugs interactions from intrinsic protein fluorescence measurements at the nanolitre scale

Protein stability and ligand‐binding affinity measurements are widely required for the formulation of biopharmaceutical proteins, protein engineering and drug screening within life science research. Current techniques either consume too much of often precious biological or compound materials, in large sample volumes, or alternatively require chemical labeling with fluorescent tags to achieve measurements at submicrolitre volumes with less sample. Here we present a quantitative and accurate method for the determination of protein stability and the affinity for small molecules, at only 1.5–20 nL optical sample volumes without the need for fluorescent labeling, and that takes advantage of the intrinsic tryptophan fluorescence of most proteins. Coupled to appropriate microfluidic sample preparation methods, the sample requirements could thus be reduced 85,000‐fold to just 10⁸ molecules. The stability of wild‐type FKBP‐12 and a destabilizing binding‐pocket mutant are studied in the presence and absence of rapamycin, to demonstrate the potential of the technique to both drug screening and protein engineering. The results show that 75% of the interaction energy between FKBP‐12 and rapamycin originates from residue Phe99 in the binding site.