Kouroush Salimi

Bio: Kouroush Salimi is an academic researcher from Yıldırım Beyazıt University. The author has contributed to research in topics: Organoclay & Visible spectrum. The author has an hindex of 11, co-authored 33 publications receiving 407 citations. Previous affiliations of Kouroush Salimi include Hacettepe University.

Highly selective magnetic affinity purification of histidine-tagged proteins by Ni2+ carrying monodisperse composite microspheres

Abstract: A magnetic sorbent with stable and superior magnetic behaviour was developed for His-tagged protein purification by immobilized metal affinity chromatography (IMAC). Magnetic, monodisperse and porous silica microspheres 6 μm in size, with bimodal pore size distribution including both mesoporous and macroporous compartments were synthesized as the base material by a staged-shape template hydrolysis & condensation protocol. The magnetic microspheres were functionalized with iminodiacetic acid (IDA) and Ni2+ ions were attached onto the microspheres by metal-chelate formation via carboxyl groups. The saturation magnetization and carboxyl content of IDA attached magnetic silica microspheres were determined as 22.1 emu g−1 and 19 mmol IDA g−1 microspheres, respectively. A superior magnetic response with respect to the currently available IMAC sorbents in the form of composite magnetic nanoparticles was obtained with the proposed sorbent. The magnetic sorbent was utilized for the isolation of His-tagged green fluorescent protein (GFP) from E. coli lysate in batch-fashion. The maximum equilibrium GFP adsorption was ca. 87 mg GFP per g sorbent. GFP was isolated with high selectivity (>95% purity) and isolation yields up to 68% by changing the magnetic sorbent concentration. The superior isolation performance of the sorbent was explained by the presence of a bimodal pore structure including both macropores facilitating the intraparticular diffusion of GFP, and the mesopores serving a large surface area for parking and adsorption of GFP into the microbeads.

Microwave-assisted rapid synthesis of poly(glycerol-sebacate) elastomers

Abstract: Poly(glycerol-sebacate) (PGS) was introduced a decade ago as a potential material for soft tissue repair. All of the proposed copolymerization reactions in the literature include a two-stage (prepolymerization and curing) synthesis where the reaction times can take as long as several days. This study, on the other hand, proposes a new route that eliminates these disadvantages and enables a rapid synthesis of PGS elastomers via microwave-assisted prepolymerization in minutes instead of days. No purge gas, catalyst or vacuum is needed in the first prepolymerization step. The curing stage was carried out at 150 °C for 4, 8, 16, and 24 hours. The glass transition temperature (Tg) and melting temperatures for the glycerol and sebacic acid fragments (Tm1 and Tm2) of these PGS elastomers were found as −35.61 °C, −15.82 °C, and 61.70 °C, respectively. The Young's modulus and tensile strength values were found as 0.50 ± 0.02 MPa and 0.27 ± 0.06 MPa, respectively.

Core/Shell PDA@UiO-66 Metal–Organic Framework Nanoparticles for Efficient Visible-Light Photodegradation of Organic Dyes

Abstract: In this study, bio-inspired polydopamine nanoparticles (PDA NPs) were utilized as a starting template to fabricate a well-defined zirconium-based MOF (UiO-66, PDA@MOF) core/shell heteronanostructur...

A Boronate Affinity-Assisted SERS Tag Equipped with a Sandwich System for Detection of Glycated Hemoglobin in the Hemolysate of Human Erythrocytes

Abstract: Phenylboronic acid-functionalized, Ag shell-coated, magnetic, monodisperse polymethacrylate microspheres equipped with a glycoprotein-sensitive sandwich system were proposed as a surface-enhanced Raman scattering (SERS) substrate for quantitative determination of glycated hemoglobin (HbA1c). The magnetization of the SERS tag and the formation of the Ag shell on the magnetic support were achieved using the bifunctional reactivity of newly synthesized polymethacrylate microspheres. The hemolysate of human red blood cells containing both HbA1c and nonglycated hemoglobin was used for determination of HbA1c. The working principle of the proposed SERS tag is based on the immobilization of HbA1c by cyclic boronate ester formation between glycosyl residues of HbA1c and boronic acid groups of magnetic polymethacrylate microspheres and the binding of p-aminothiophenol (PATP)-functionalized Ag nanoparticles (Ag NPs) carrying another boronic acid ligand via cyclic boronate ester formation via unused glycosyl groups o...

Global Analysis of Protein Phosphorylation in Yeast

Abstract: Protein phosphorylation is estimated to affect 30% of the proteome and is a major regulatory mechanism that controls many basic cellular processes. Until recently, our biochemical understanding of protein phosphorylation on a global scale has been extremely limited; only one half of the yeast kinases have known in vivo substrates and the phosphorylating kinase is known for less than 160 phosphoproteins. Here we describe, with the use of proteome chip technology, the in vitro substrates recognized by most yeast protein kinases: we identified over 4,000 phosphorylation events involving 1,325 different proteins. These substrates represent a broad spectrum of different biochemical functions and cellular roles. Distinct sets of substrates were recognized by each protein kinase, including closely related kinases of the protein kinase A family and four cyclin-dependent kinases that vary only in their cyclin subunits. Although many substrates reside in the same cellular compartment or belong to the same functional category as their phosphorylating kinase, many others do not, indicating possible new roles for several kinases. Furthermore, integration of the phosphorylation results with protein-protein interaction and transcription factor binding data revealed novel regulatory modules. Our phosphorylation results have been assembled into a first-generation phosphorylation map for yeast. Because many yeast proteins and pathways are conserved, these results will provide insights into the mechanisms and roles of protein phosphorylation in many eukaryotes.

Genesis of Pure Se(0) Nano- and Micro- structures in Wastewater

Abstract: Advanced materials are essential to the quality of modern day life, but the synthesis of these compounds is often inefficient in terms of energy, time and resources; especially when considering the hydrothermal batch methods used to prepare many such compounds – often requiring week-long reaction times with variable yields and product quality. In contrast, Continuous flow synthesis (CFS) provides a more readily scalable means for the efficient, effective and reproducible synthesis of inorganic compounds. This publication demonstrates the novel CFS of several metal ammonium phosphates and compare the effect of synthesis route on particle size, size distribution, and crystallinity.