Immobilization of a thermostable α-amylase, Termamyl, onto nitrocellulose membrane by Cibacron Blue F3GA dye binding

Highly porous nitrocellulose membranes were prepared by a solvent casting technique for the first time to immobilize α-amylase. An affinity dye, namely Cibacron Blue F3GA (CB), was incorporated covalently within the structure. The nitrocellulose–CB derivatized membranes were used for the immobilization of a starch degrading enzyme, α-amylase. Optimum conditions of immobilization for highest apparent activity were determined as pH 6.0, temperature 50°C and initial enzyme concentration 0.317 KNU/l. Under these optimum conditions, maximum enzyme immobilization yield was around 21% of the initial amount of the enzyme in the solution. Performance of free and immobilized enzymes at the same amount was compared for repeated runs. Up to the third use, immobilized enzyme showed higher activity than that of free enzyme mainly due to higher enzyme concentration in the membrane structure, then the apparent activity decreased gradually. However, when regenerated by switching pH to cause contraction/expansion of the structure, the membrane showed the highest activity, almost 2.5 times than that of the free enzyme. This unusual feature along with inexpensive cost may well make the nitrocellulose membrane an economical material for industrial application in glucose syrup production.     

Metabolite Profiling by Hyphenated Liquid Chromatographic Mass Spectrometric Technique (HPLC‐DAD‐ESI‐Q‐TOF‐MS/MS) and Neurobiological Potential of Haplophyllum sahinii and H. vulcanicum Extracts

In the current study, the ethanol extracts of flower, stem, and root parts of two endemic Turkish species, e. g., Haplophyllum sahinii O. Tugay & D. Uluku? and H. vulcanicum Boiss . & Heldr ., were screened against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) associated with Alzheimer's disease as well as tyrosinase (TYR) linked to Parkinson's disease using ELISA microplate assay at 200 μg/mL. Among the extracts, the highest inhibition was caused by the stem extract of H. sahinii against BChE (IC₅₀=64.93±1.38 μg/mL). Consistently, all of the extracts were found to exert a selective inhibition towards BChE to some extent. It was only the root extract of H. vulcanicum that could inhibit AChE at low level (IC₅₀=203.18±5.33 μg/mL). None of the extracts displayed an inhibition over 50 % against TYR. Metabolite profiling of the extracts was achieved by a highly hyphenated liquid chromatographic mass spectrometric technique (HPLC‐DAD‐ESI‐Q‐TOF‐MS/MS), which revealed the presence of furoquinoline (β‐fagarine, γ‐fagarine) and amide (tubasenicine, tubacetine) alkaloids; furano‐ (rutamarin), pyrano‐ (xanthyletine), and geranyloxy coumarins; phenylpropanoid (secoisolariciresinol), arylnaphthalene (mono‐O‐acetyldiphyllin apioside), and dibenzylbutyrolactone (kusunokinin, haplomyrfolin) lignans. Several important differences were observed between the extracts analyzed. β‐Fagarine was the major alkaloid in H. vulcanicum, whereas γ‐fagarine was present only in the roots of both Haplophyllum species; moreover, secoisolariciresinol and secoisolariciresinol dimethyl ether were the main lignans in the stems and flowers. This is the first study identifying ChE and TYR inhibitory effect and metabolic profiles of H. vulcanicum and H. sahinii.     

Reverse micelles of dipalmitoyl phosphatidyl choline in chloroform and their interactions with dapsone.

1H NMR studies of DiPalmitoyl Phosphatidyl Choline (DPPC) in CDCl3 at various concentrations indicate that DPPC exists as reverse micelles for concentrations beyond 6 mM. The chemical environments of the two acyl chains of DPPC are inequivalent and the inequivalence decreases with increasing DPPC concentration. At low concentrations of DPPC (less than 1.0 mM) intramolecular interactions predominate, whereas at high concentrations, intermolecular interactions predominate. Addition of water to this system, at high concentrations of the phospholipid, reduces the intermolecular interactions. In the presence of the antileprotic drug, Diamino Diphenyl Sulfone (DDS or Dapsone), significant shifts were observed only in the choline resonances of DPPC and the amino resonance of the drug, showing that the amino group of DDS interacts with the head group of DPPC.     

Effects of exotic and translocated fish species in the inland waters of Turkey

Throughout the world a number of problems have arisen following the introduction of new fish species; impacts of introductions are not limited to biological and ecological effects but may also have socioeconomic implications. Exotic and translocated fish species have become established in various parts of the inland waters of Turkey since the 1950s. The present paper reviewed ecological and economical effects of introduced freshwater fish of Turkey.     

Synthesis of novel mono and bis-indole conduritol derivatives and their α/β-glycosidase inhibitory effects

Here we synthesized four novel indole conduritol derivatives 1–4 for the first time in the literature and probed their biological activities with the α and β-glucosidases. The compounds showed quite effective glucosidase inhibitory action. IC₅₀ values of the compounds were compared with the known glucosidase inhibitor acarbose and it was determined that newly synthesized indole conduritols had more powerful effect against β-glucosidase in addition to exhibiting moderate influence against α-glucosidase. Our molecules thus constitute an important starting point for the design and exploitation of novel glucosidase inhibitors since glucosidase inhibitors have widespread applications in the treatment of diabetes, viral infections, lysosomal storage diseases and cancers.     

Disruption of the protein interaction between FAK and IGF-1R inhibits melanoma tumor growth

FAK (focal adhesion kinase) and IGF-1R (insulin-like growth factor receptor-1) directly interact with each other and thereby activate crucial signaling pathways that benefit cancer cells. Inhibition of FAK and IGF-1R function has been shown to significantly decrease cancer cell proliferation and increase sensitivity to chemotherapy and radiation treatment. As a novel approach in human melanoma, we evaluated the effect of a small-molecule compound that disrupts the protein interaction of FAK and IGF-1R. Previously, using virtual screening and functional testing, we identified a lead compound (INT2–31) that targets the known FAK-IGF-1R protein interaction site. We studied the ability of this compound to disrupt FAK-IGF-1R protein interactions, inhibit downstream signaling, decrease human melanoma cell proliferation, alter cell cycle progression, induce apoptosis and decrease tumor growth in vivo. INT2–31 blocked the interaction of FAK and IGF-1R in vitro and in vivo in melanoma cells and tumor xenografts through precluding the activation of IRS-1, leading to reduced phosphorylation of AKT upon IGF-1 stimulation. As a result, INT2–31 significantly inhibited cell proliferation and viability (range 0.05–10 μM). More importantly, 15 mg/kg of INT2–31 given for 21 d via intraperitoneal injection disrupted the interaction of FAK and IGF-1R and effectively decreased phosphorylation of tumor AKT, resulting in significant melanoma tumor regression in vivo. Our data suggest that the FAK-IGF-1R protein interaction is an important target, and disruption of this interaction with a novel small molecule (INT2–31) has potential anti-neoplastic therapeutic effects in human melanoma.