Overexpression,one-step purification,and characterization of a type II cholesterol oxidase from a local isolate <Emphasis Type="Italic">Rhodococcus</Emphasis> sp. PTCC 1633

A 1.6 kb gene encoding a cholesterol oxidase (choR) from a local isolate, Rhodococcus sp. PTCC 1633 was cloned into pET23a and the highly expressed recombinant enzyme was purified from the cell lysate of IPTG-induced Escherichia coli BL21(DE3)pLysS with one-step absorption on cholesterol. The purified protein had a molecular mass of 55 kDa, isoelectric point at about pH 9.0 and absorption peaks at 280, 380 and 460 nm, indicating that the enzyme is a flavoprotein. The optimum pH and temperature for the recombinant enzyme were 7.0 and 50°C, respectively. Steady-state kinetic revealed that the cholesterol oxidase had a K _m of 32 μM. This study is the first report concerning expression and one-step purification of a gene encoding cholesterol oxidase from Rhodococcus spp. This study revealed that this enzyme is a type II cholesterol oxidase.     

Absence of mutations in GJB2 (Connexin-26) gene in an ethnic group of southwest Iran

BACKGROUND:

The common GJB2 gene mutation (35delG) has been previously reported from Iranian patients that were affected with nonsyndromic autosomal recessive deafness. We, therefore, for the first time, investigated the prevalence and frequency of the GJB2 gene mutation in the Iranian deaf population with Arabian origins.

MATERIALS AND METHODs:

We amplified and sequenced the entire coding sequence of the GJB2 gene from 61 deaf patients and 26 control subjects.

RESULT:

None of the analyzed samples revealed deafness-associated mutation.

CONCLUSION:

This finding differs from several reports from Iran as we have focused on the GJB2 gene that possesses various mutations as the cause of congenital recessive deafness.     

Safely removing cell debris with LC3‐associated phagocytosis

Phagocytosis and autophagy are two distinct pathways that degrade external and internal unwanted particles. Both pathways lead to lysosomal degradation inside the cell, and over the last decade, the line between them has blurred; autophagy proteins were discovered on phagosomes engulfing foreign bacteria, leading to the proposal of LC3‐associated phagocytosis (LAP). Many proteins involved in macroautophagy are used for phagosome degradation, although Atg8/LC3 family proteins only decorate the outer membrane of LC3‐associated phagosomes, in contrast to both autophagosome membranes. A few proteins distinguish LAP from autophagy, such as components of the autophagy pre‐initiation complex. However, most LAP cargo is wrapped in multiple layers of membranes, making them similar in structure to autophagosomes. Recent evidence suggests that LC3 is important for the degradation of internal membranes, explaining why LC3 would be a vital part of both macroautophagy and LAP. In addition to removing invading pathogens, multicellular organisms also use LAP to degrade cell debris, including cell corpses and photoreceptor outer segments. The post‐mitotic midbody remnant is another cell fragment, which results from each cell division, that was recently added to the growing list of LAP cargoes. Thus, LAP plays an important role during the normal physiology and homoeostasis of animals.     

Microbial production of testosterone and testololactone in the culture of <Emphasis Type="Italic">Aspergillus terreus</Emphasis>

Two metabolites were obtained by microbial transformation of androstendione in the culture of Aspergillus terreus PTCC 5283, a fungus isolated from soil. Their structures were established as testosterone and testololactone on the basis of the spectral data including ¹H NMR, ¹³C NMR, FTIR, MS and physical constants such as melting point and optical rotation. Aspergillus terreusproduced both metabolites after 3 days incubation at 27 °C. The bioconversion reactions observed were 17-carbonyl reduction and biological Baeyer–Villiger oxidation.     

Predictors of postoperative atrial fibrillation after coronary artery bypass graft surgery

Objectives

The present study was aimed to identify the preoperative, intraoperative, and postoperative predictors of AF in a pure cohort of the patients with coronary artery disease who underwent CABG surgery.

Methods

Between November 2005 and May 2006, 302 consecutive patients were included in this prospective study. All the relevant clinical, electrocardiographic, echocardiographic, and laboratory data were gathered in the included patients and they were also monitored for development of post-CABG AF.

Results

Postoperative AF occurred in 46 (15%) of patients. By univariate analysis, older age, P-wave abnormality in ECG, presence of mitral regurgitation, larger left atrium (LA), left main coronary artery involvement, failure to graft right coronary artery (RCA), and adrenergic use in ICU were significantly associated with occurrence of post-CABG AF (all P< 0.05). However, in the logistic regression model, age (OR: 1.067, 95%CI: 1.02-1.116, P=0.005), LA dimension (OR: 1.102, 95%CI: 1.017-1.1936, P=0.017), P-wave morphology (OR: 12.07, 95%CI: 3.35-48.22, P=0.0001), failure to graft RCA (OR: 3.57, 95%CI: 1.20-10.64, P=0.022), and postoperative adrenergic use (OR: 0.35, 95%CI: 0.13-0.93, P=0.036) remained independently predictive of postoperative AF.

Conclusion

The present study suggested that age, P-wave morphology, LA dimension, failure to graft right coronary artery, and postoperative adrenergic use were independent predictors of post-CABG AF. Therefore, clinical data, ECG and echocardiography may be useful in preoperative risk stratification of the surgical patients for the occurrence of post-CABG AF.     

Umbelliprenin from Ferula persica roots inhibits the red pigment production in Serratia marcescens

The chloroform extract of Ferula persica var. persica roots was found to inhibit red pigment production of Serratia marcescens. A bioguided fractionation study by preparative thin layer chromatography (PTLC) detected a fraction (Rf = 0.71, petroleum ether/EtOAc, 2:1 v/v), which was effective on depigmentation of Serratia marcescens. Using conventional spectroscopy methods, the active fraction was identified as umbelliprenin. Neither the chloroform extract nor the isolated umbelliprenin fraction showed any antibacterial activity against the test strain at a certain concentration. In contrast, they exhibited depigmentation zones on culture plates.     

A Role for the Insulin Receptor in the Suppression of Dengue Virus and Zika Virus in Wolbachia-Infected Mosquito Cells

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Smac mimetics as novel promising modulators of apoptosis in the treatment of breast cancer

Breast cancer is the most prevalent cancer in women. Despite improvements in treatment, the rate of breast cancer-related deaths is still high, and this issue needs further, accurate investigations. Although several treatment options are available, none of them are efficient for complete remission, particularly in advanced stages of the disease. It is known that cancerous cells have dysregulated apoptosis-related pathways, by which they can remain alive for a long time, expand freely, and escape from apoptosis-inducing drugs or antitumor immune responses. Therefore, modulation of apoptosis resistance in cancer cells may be an efficient strategy to overcome current problems faced in the development of immunotherapeutic approaches for the treatment of breast cancer. The inhibitors of apoptosis protein (IAPs) are important targets for cancer therapy because it has been shown that these molecules are overexpressed and highly active in various cancer cells and suppress apoptosis process in malignant cells by blockage of caspase proteins. There is evidence of Smac mimetics efficacy as a single agent; however, recent studies have indicated the efficacy of current anticancer immunotherapeutic approaches when combined with Smac mimetics, which are potent inhibitors of IAPs and synthesized mimicking Smac/Diablo molecules. In this review, we are going to discuss the efficacy of treatment of breast cancer by Smac mimetics alone or in combination with other therapeutics.     

Effect of NMDA receptor agonist and antagonist on spermatogonial stem cells proliferation in 2- and 3- dimensional culture systems

Molecular Biology Reports - The main purpose of this study was to investigate the effect of D-serine (DS) and Dizocilpine (MK-801) on the proliferation of spermatogonial stem cells (SSCs) in...