New and different lignocellulosic materials from Turkey for laccase and manganese peroxidase production by Trametes versicolor

In the present study, the production of laccase (Lac) and manganese‐dependent peroxidase (MnP) by the white‐rot fungus Trametes versicolor grown in submerged cultures with different agricultural residues was investigated. The lignocellulosic materials studied were almond shells, hazelnut husks, sunflower stems, clover straw and hazelnut cobs, because they are common agricultural wastes in Turkey. Among the different lignocellulosic materials studied, hazelnut cobs provided the highest Lac and MnP activities (47.09 and 109.21 U/L, respectively). The optimum conditions were determined for Lac and MnP production in submerged cultures of T. versicolor by using hazelnut cobs as substrate. For Lac production, the optimum incubation time, hazelnut cob concentration, pH, and shaking rate were found as 4 days, 2% w/v, 6.0 and 130 rpm, respectively. For MnP production, the optimum incubation time, hazelnut cob concentration, pH and shaking rate were found as 5 days, 2% w/v, 6.0 and 90 rpm, respectively.     

Tip60 might be a candidate for the acetylation of hepatic carbonic anhydrase I and III in mice

Molecular Biology Reports - Carbonic anhydrases (CAs) play a significant role in maintaining pH balance by catalyzing the conversion of carbon dioxide to bicarbonate. The regulation of pH is...     

Miocene spores and pollen from Pelitçik Basin,Turkey–environmental and climatic implications

The palynological investigation of the early Middle Miocene fluviolacustrine sedimentary rocks interfingering with volcanics of the Galatean Volcanic Province at Pelitçik Basin (Central Turkey) have yielded palynomorphs belonging to 51 spore and pollen taxa. The pollen record is dominated by Ulmus, Pinaceae, Quercus, Carpinus and Carya, and appears to reflect climatic conditions. Two pollen zones were established based on changing abundances of plant taxa. Zone 1 is characterized by dominance of Ulmus and Pinaceae. Zone 2 is differentiated and characterized by a dramatic increase in, and predominance of, Ulmus, Carya, deciduous Quercus, Carpinus, Salix and Pinaceae. Mixed mesophytic forests were widespread in the basin suggesting warm and temperate climate. The decreasing relative percentage of thermophilous taxa, with Engelhardia as the main component, and warm temperate taxa, such as Carya, at the upper part of Zone 2 generally indicates a climatic deterioration, probably related to the Middle Miocene cooling.     

A computer-based model for the regulation of mitogen activated protein kinase (MAPK) activation

Computer simulations and mathematical modeling of biological processes are becoming increasingly popular, and yet the complexity of the biochemical systems or the differences between experimental setups make it very difficult to establish a standard formula for these modeling projects. Before we can start using computer-based models for predictions or targeted experiment designs, it is very important to establish a reliable model on which those predictions can be based and experimentally tested. Here we attempt to present a computer model for the mitogen-activated protein kinase (MAPK) signaling cascade which is consistent with previously published experimental results. In this study we have focused our attention to a generic MAPK ERK (extracellular signal-regulated kinase) pathway activated by epidermal growth factor (EGF) in an attempt to understand how receptors may achieve different activation kinetics of the MAPK signaling. We successfully show that the level of receptor expression is one key determinant in this regulation, and that the binding affinity of the active receptor to adaptor proteins can have a small but albeit direct effect on the downstream activation.     

The effects of age and gender on the relationship between HMGCR promoter-911 SNP (rs33761740) and serum lipids in patients with coronary heart disease

Background

Hydroxymethylglutaryl-Coenzyme A Reductase (HMGCR) catalyzes the rate-limiting step of cholesterol biosynthesis. This enzyme is the target of the widely available cholesterol lowering statins. In this population-based case–control study, the frequencies of -911 C>A polymorphism (rs3761740) of the HMGCR gene in patients with coronary heart disease (CHD) and healthy subjects were investigated and the correlations between the different genotypes and hypercholesterolemia with cardiovascular risk factors were analyzed.

Methods

The HMGCR genotypes were determined in 365 patients with CHD and 365 controls by PCR–RFLP assay. Anthropometric measurements were measured in all participants.

Results

There was no significant difference in the genotype frequencies of the HMGCR polymorphism between the male subjects of both patient and control groups, however, the HMGCR-CC genotype was found to be more frequent in female patients with CHD than female controls (p = 0.002). The HMGCR-CC genotype showed higher total-cholesterol (TC) and LDL-cholesterol (LDL-C) levels than the CA + AA genotypes in male CHD patients (p = 0.018). Due to this significant sex interaction, a multivariate analysis was conducted on the patient group. In the multivariate logistic regression analysis, the HMGCR-CC genotype was significantly associated with age < 55 (OR = 2.837, p = 0.001) and TC ≥ 5.18 mmol/L (OR = 1.970, p = 0.027) in male subjects. However, this association was not observed in female patients (p > 0.05). This analysis confirmed that the HMGCR-CC genotype was associated with elevated TC levels in male CHD patients with age < 55 years.

Conclusion

These results suggest that age and sex modify the contribution of the HMGCR-911 polymorphism to fasting serum TC, LDL-C levels and risk of CHD.     

Novel polymeric microspheres: Synthesis,enzyme immobilization,antimutagenic activity,and antimicrobial evaluation against pathogenic microorganisms

New polymeric microspheres containing azomethine ( 1a ‐ 1c and 2a ‐ 2c ) were synthesized by condensation to compare the enzymatic properties of the enzyme glucose oxidase (GOx) and to investigate antimutagenic and antimicrobial activities. The polymeric microspheres were characterized by elemental analysis, infrared spectra (FT‐IR), proton nuclear magnetic resonance spectra, thermal gravimetric analysis, and scanning electron microscopy analysis. The catalytic activity of the glucose oxidase enzyme follows Michaelis‐Menten kinetics. Influence of temperature, reusability, and storage capacity of the free and immobilized glucose oxidase enzyme were investigated. It is determined that immobilized enzymes exhibit good storage stability and reusability. After immobilization of GOx in polymeric supports, the thermal stability of the enzyme increased and the maximum reaction rate (V_max) decreased. The activity of the immobilized enzymes was preserved even after 5 months. The antibacterial and antifungal activity of the polymeric microspheres were evaluated by well‐diffusion method against some selected pathogenic microorganisms. The antimutagenic properties of all compounds were also examined against sodium azide in human lymphocyte cells by micronuclei and sister chromatid exchange tests.     

Purification and partial characterization of manganese peroxidase from immobilized Phanerochaete chrysosporium

Solid-state culture of the white-rot fungus Phanerochaete chrysosporium BKMF-1767 (ATCC 24725) has been carried out, using an inert support, polystyrene foam. Suitable medium and culture conditions have been chosen to favor the secretion of manganese peroxidase (MnP). The enzyme was isolated and purified from immobilized P. chrysosporium and partially characterized. Partial protein precipitation in crude enzyme was affected using ammonium sulphate, polyethylene glycol, methanol, and ethanol methods. Fractionation of MnP was performed by DEAE-Sepharose ion exchange chromatography followed by Ultragel AcA 54 gel filtration chromatography. This purification attained 23.08% activity yield with a purification factor of 5.8. According to data on gel filtration chromatography and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), the molecular weight of the enzyme was 45 000±1000 Da. The optimum pH and temperature of purified MnP were 4.5 and 30 °C, respectively. This enzyme was stable in the pH range 4.5–6.0, at 25 °C and also up to 35 °C at pH 4.5 for 1 h incubation period. MnP activity was inhibited by 2 mM NaN₃, ascorbic acid, β-mercaptoethanol and dithreitol. The K_m values of MnP for hydrogen peroxide and 2.6-dimetoxyphenol were 71.4 and 28.57 μM at pH 4.5, respectively. The effects of possible inhibitors and activators of enzyme activity were investigated.     

Atorvastatin has cardiac safety at intensive cholesterol-reducing protocols for long term, yet its cancer-treatment doses with chemotherapy may cause cardiomyopathy even under coenzyme-Q10 protection

Statins provide strong clinical benefits via reducing stroke deaths, and they are also considered for tumor reduction and chemo-sensitization. High dose atorvastatin in adults (80 mg daily, approx. 1 mg/kg) is proven to afford greater protection against cardiac deaths than does a standard lipid-lowering dose in coronary syndrome. For cancer trials, mega doses up to 30 mg/kg have been used for short term treatments but neither a high nor a mega-dose of atorvastatin has been tested for long term cardiac safety. This may be of special concern, since some animal studies showed deleterious effects of statins on cardiac tissue, which may be related with coenzymeQ (CoQ) depletion. We performed an electron microscopic analysis of rat hearts after low, high-or mega-dose atorvastatin therapy and with or without MNU (methyl-nitrosourea)-stress. MNU + daily high dose atorvastatin treatment for 13 months did not produce severe cardiac toxicity with CoQ. However, at mega doses (30 mg/kg) and with MNU, mitochondrial damage and myofibrillary disintegration was obvious. Strong proliferation of mitochondria under high dose atorvastatin therapy with CoQ may explain the lack of cardiotoxicity; and this finding seems to parallel recent data that statins induce HNF-4 and PPAR-alpha, both responsible for mitochondria-proliferation. Employment of statins for tumor chemo-sensitization at high-dosage and for long term treatments may require strategies to direct the mevalonate-entry differentially into cardiac and tumor cells and to develop a protocol analogous to folic acid salvage of methotrexate toxicity.