Erol Erçağ

Human serum albumin (HSA) is a ubiquitous, multifunctional protein responsible for the systemic distribution of both endogenous metabolites and exogenous pharmaceuticals. Its inherent properties, particularly its ability to seep into tissues and its multiple ligand-binding sites, have rendered HSA an attractive vehicle for nanoparticle-based drug delivery systems, particularly for cancer targeting. In this study, we present high-resolution crystallographic data revealing two distinct dimerization patterns of HSA (Protein Data Bank [PDB] ID: 9V61) obtained under high-concentration crystallization conditions, along with results from dipyridamole docking. Both dimer types demonstrate extensive interface areas and a significant number of electrostatic interactions. Comparative analysis with a previously reported dimer structure (PDB ID: 3JQZ) and other high-interface-area structures (PDB ID: 5Z0B, PDB ID: 8CKS) indicates similarities in contact regions but unique residue-level differences in bonding interactions. Interface surface area distribution and space group histograms further support the rarity and potential physiological relevance of the identified dimer forms. Importantly, these dimer configurations do not disrupt Sudlow’s drug-binding sites, as the dipyridamole docking analysis shows strong affinity for sites I and III without affecting their utility in engineered drug delivery. Our findings open new avenues for structure-based mutagenesis and nanoparticle design strategies centered on HSA dimerization dynamics.

Human serum albumin (HSA) is a ubiquitous, multifunctional protein responsible for the systemic distribution of both endogenous metabolites and exogenous pharmaceuticals. Its inherent properties, mainly its ability to seep into the tissues and multiple ligand-binding sites, have rendered HSA an attractive vehicle in nanoparticle-based drug delivery systems, particularly in cancer targeting. In this study, we present high-resolution crystallographic data revealing two distinct dimerization patterns of HSA (PDB ID: 9V61), obtained under high-concentration crystallization conditions, in addition to results from dipyridamole dockings. Both dimer types demonstrate extensive interface areas and a significant number of electrostatic interactions. Comparative analysis with previously reported dimer structure (PDB ID: 3JQZ) and other high-interface-area structures, (PDB ID: 5Z0B, PDB ID: 8CKS) indicates similarities in contact regions, but unique residue-level differences in bonding interactions. Interface surface area distribution and space group histograms further support the rarity and potential physiological relevance of the identified dimer forms. Importantly, these dimer configurations do not disrupt Sudlow’s drug-binding sites, which is important as the dipyridamole docking analysis presents strong affinity to Sudlow site I and Sudlow site III, not affecting their utility in engineered drug delivery. Our findings open new avenues for structure-based mutagenesis and nanoparticle design strategies centered on HSA dimerization dynamics.

Sanguinaria canadensis L. is an herbalceous perennial that contains benzophenanthridine alkaloids, including sanguinarine and dihydrosanguinarine. Mannan-oligosaccharide (MOS) is derived from the cell wall of the yeast Saccharomyces cerevisiae. The aim of the study was to investigate the effects of the supplementation of Sanguinaria canadensis extract (SCE) and/or MOS on body weight and serum total antioxidant activity in broilers under heat stress (HS[+]) and normal (HS[-]) conditions. A total of 72 one-day-old Ross 308 broiler were randomly assigned to 8 pens in two environmentally controlled rooms (4 pens per room). The dietary treatments were: (1) basal diet (control), (2) basal diet plus 1 g/kg of SCE, (3) basal diet plus 1 g/kg of MOS, (4) basal diet plus 1 g/kg of SCE and 1 g/kg of MOS. At 15 days of age, the chickens in one of the two rooms were exposed to HS (34±2°C) for 6 h, while the chickens in another room were continuously kept under normal conditions, serving as control treatment (22±2°C). During the study, body weights were significantly different and these differences were depended on diet and heat. HS[+] groups had lower body weights, however, the supplementation of SCE and MOS improved this situation positively. During the study, it was also determined that there was an interaction between diet and heat. Differences for serum antioxidant activity between HS[-] and HS[+] groups were significant for CUPRAC analysis results and unsignificant for ABTS analysis results.

This study deals with the investigation of cyfluthrin, cypermethrin, deltamethrin, and malathion residues in local honey samples from Gümüşhane, Turkey. The determination was performed with GC/MS-MS method with HP-5MS column under certain conditions: 120 ℃ oven temperature, 250 ℃ injection temperature, 121.9 kPa pressure and 1.2-1.8 mL/min flow rates. The samples were picked from eighteen stations of Gümüşhane. Standard addition method was employed in chromatographic determination. No pesticide detected in samples of fifteen stations, nevertheless, subjected pesticides were determined in samples collected from other three stations. The residue levels varied from 0.18 mg/kg to 9.50 mg/kg at 1.5 mL/min flow rate. The results were also evaluated with Box-Behnken Design (BBD) optimization. Multivariate experimental design (flow rate and station, pesticide type) was employed for constructing quadratic models. Regression analysis showed that the experimental results and the predictive values yielded by model are quite close to each other with determination coefficient (R2) of 0.985.

Nowadays, with excessive use due to rapid population growth, growing industry, and technological developments, environmental pollution is also increasing and is reaching a point where it threatens the health of humans. The alarming increase in environmental pollution is mostly seen in the form of water pollution. Water pollution has reached levels that threaten human health. There are difficulties in accessing clean water in many parts of the world as a result of restricting the use of natural water resources polluted by both human activities and natural causes. Therefore, intense efforts are made to remove especially heavy metals and other harmful substances that pollute water. Among these toxic heavy metals threatening the health of humans, arsenic is at the top of the list as the most dangerous one. In recent years, many methods and techniques have been developed in addition to classical methods for removing pollutants from water. In this study, conventional methods used in the treatment of arsenic-contaminated waters, the difficulties encountered in the removal process, and the advantages and disadvantages of the methods were critically reviewed in the light of current and past information. In addition, detailed comparative information is given about nano-sized adsorbents, which is an innovative approach used in the adsorption method, one of the arsenic removal methods.