Protein and Peptide Letters - Volume 25, Issue 6, 2018

Background: Targeted therapy has been widely used in the treatment of patients with metastatic renal cell carcinoma. The current available therapies focus on the inhibition of angiogenesis through targeting the vascular endothelial growth factor receptor, and protein kinase such as the mammalian target of rapamycin. Compared with other traditional chemotherapies and radiotherapies, targeted therapies dramatically improved progression-free survival. However, microenvironment of patients' body, drug-drug interactions, as well as polymorphisms of metabolic enzymes and drug transporters ABC could influence pharmacokinetic characteristics. Therefore, targeted therapy has been shown to present a large interindividual variability. Therapeutic drug monitoring is the clinical practice aims at improving efficacy and reducing toxicity by measuring drug concentration in biological samples and adjusting drug dose for each individual. Conclusion: Therapeutic drug monitoring is widely employed under the situations such as lacking of therapeutic response, emerging of severe or unexpected toxicities, with narrow therapeutic windows or potential drug-drug interactions. The development of Therapeutic drug monitoring in targeted therapy have been proposed in recent years, more and more targeted therapies are benefit from therapeutic drug monitoring. It is showed significant benefit in the individual targeted treatment of metastatic renal cell carcinoma.

Background: Irisin; a novel myokine/adipokine; encoded by FNDC5 gene have been suggested to play an important role in energy metabolism and obesity. However, the genetic variations at this locus and their effects on different metabolic parameters is still poorly understood. Aim: This study aimed to investigate the role of FNDC5/irisin gene polymorphisms (RS16835198 and RS726344) in obese individuals and their genotype phenotype correlation with circulating serum irisin level and other biochemical parameters like glucose, lipid metabolism and liver enzymes. Methods: The study included 200 subjects divided into two groups: obese group (110 subject) and control non obese group (90 subject). All selected individuals were subjected to a comprehensive questionnaire, clinical assessment and laboratory investigations including fasting blood glucose (FBS), serum insulin, lipid profile (Total Cholesterol (TC), Triglycerides (TG), Low Density Lipoprotein (LDLc), High Density Lipoprotein (HDLc), liver enzymes (ALT, AST, GGT), Serum irisin level and HOMA-IR was calculated. DNA extraction and FNDC5 allelic discrimination analysis for FNDC5 SNPs, rs16835198and rs726344 using the TaqMan SNP genotyping assays by Real time PCR. Results: In obese group; serum irisin was significantly lower (0.55 ± 0.2) than control group (1.7 ± 0.3) P value < 0.001. Regarding genotype and allele frequency, T allele of rs16835198 polymorphism is associated with high BMI, high total cholesterol, TG and LDL-C, low level of serum HDL-C, high FBS, low serum insulin, low HOMA-IR and low serum level of irisin. While G allele of rs726344 is significantly associated with high BMI, FBS, low serum insulin and HOMA-IR, High total cholesterol, TG, LDL-C, low level of HDL-C and low serum irisin. Conclusion: Our data suggest that FNDC5 SNPs, rs16835198and rs726344 are associated with obesity in Egyptian population. GG genotype and G allele of rs726344 variant and TT genotype and T allele of rs16835198 variant may increase the susceptibility to obesity and there were a genotype phenotype correlation with circulating serum irisin and several metabolic parameters.

Background: The hyaluronic acid receptor CD44, is a cancer stem cell biomarker, playing important roles in cell adhesion, tumor progression and drug-resistance. Therefore, CD44 is a potential target for cancer treatment and its blockade could result in multi-factorial therapeutic effects. Methods: Nanobodies against CD44 were isolated from a synthetic library with a diversity of 5×1011 CFU/ml using the phage display technique. Three approaches were used for isolation of nanobodies fragments including peptide-, protein- and cell-based panning. Results: Nanobodies from cell-based panning displayed more specificity compared to protein or peptide-based panning. Our results show that cell-based panning is the most efficient method for isolation of a specific single domain antibody fragment to CD44 from a synthetic phage displayed library. Conclusion: The isolated nanobodies could successfully recognize and bind cells that express the CD44 surface antigen.

Background: Unstructured regions in proteins can vary from several amino acid residues to a completely disordered sequence. Since such regions play an important role in the protein functioning, much attention is being paid to their prediction. Special different programs are available for this purpose; however, predictions obtained vary from protein to protein. Objective: In this article, our motivation is the investigation of the high prediction accuracy of flexible loops in G-proteins family with FoldUnfold program due to crucial functions associated with these regions. Method: For prediction of loops in the G-proteins we used programs as RONN, DisEMBL, Glob- Plot2, IUPred, PONDR, FoldIndex, MobiDB and FoldUnfold. As a criterion of reliability of predicting disordered regions, we have chosen comparison with the regions known from the 3D structures. Collection, data analysis and statistical analysis were performed using Python 3.3. and R version 3.2.0. Results: For 23 G-proteins, the FoldUnfold program predicts loops with the average precision of 60-80%. It is seen that our program enables better prediction of loop positions than other programs. Statistically significant weak negative correlation exists between the average number of closed residues according to the FoldUnfold program and the Debye-Waller factors. Investigations of the G-proteins with the posttranslational modifications revealed additional flexible properties of the residues involved in the attachment of fatty acids. Conclusion: Our research demonstrates additional possibilities and the high prediction accuracy of the FoldUnfold program for prediction of flexible regions and characteristics of individual residues in different protein family.

Background: Ribonucleases of T2 family are ubiquitous cellular components which have played several biological functions in molecular and pharmaceutical fields. Objective: Therefore, a soluble and highly active RNase belonging to T2 family was screened from Bacillus megaterium NRRL 3712, and different cultivation strategies were applied to enhance the production of enzyme. Method: A high-level of an extracellular RNase and cell density was produced using optimal cultivation conditions. A monomeric enzyme with a molecular mass of 45 kDa, was purified to homogeneity using acetone precipitation and ion-exchange chromatography. Results: Purified enzyme was optimally activity at 45°C and pH 7.0, and it displayed a half-life of 26 min at 64°C. It was quite stable up to 60 min at 40-50°C temperature and over a broad range of pH 4.5-8.0. It showed great substrate specificity with yeast RNA, poly (A), poly (G), poly (C), and poly (U). Kinetic parameters such as Km, Vmax, kcat and kcat Km -1 values against yeast RNA as substrate, were 71.67 μg mL-1, 7866.4 μmol mg-1min-1, 17669.4 sec-1, and 246.53, respectively. Conclusion: The article provides a valuable novel RNase which exhibited great resistance against various organic solvents, detergents and metal ions, whereas its activity was stimulated up to 142% by adding 5 mM EDTA. Hence, dictates its applicability as therapeutic agent and in various other biotechnological fields.