NOPR Collection:

Deciphering the binding modes of hematoporphyrin to bovine serum albumin

Sun, 01 Jun 2014 00:00:00 GMT

Title: Deciphering the binding modes of hematoporphyrin to bovine serum albumin Authors: Ahmed, Mohammed; Guleria, Apurav; Singh, Ajay K; Bandyopadhyay, Tusar; Sarkar, Sisir K Abstract: Interaction of proteins with small molecules is important in understanding delivery and transport of different therapeutic agents, including drugs. In the present study, we investigated the interaction between hematoporphyrin (HP), the principal component of photosensitizing drug with bovine serum albumin (BSA) in aqueous buffer solution using UV-Vis absorption spectroscopy and fluorescence measurements. The results were further substantiated by molecular docking and molecular dynamics (MD) simulation. Our results revealed that fluorescence of BSA was dominantly quenched by the ground-state complex formation with HP accompanied by the electronic energy transfer (EET) to the later. We experimentally determined the thermodynamic parameters such as G⁰, H⁰, and S⁰ for the HP-BSA system which were -35.5 kJ mole^-1, -56.4 kJ mole^-1 and -0.06 kJ mole^-1K^-1, respectively. These parameters suggested hydrogen-bonding and Van der Waals forces playing major role in the complexation. This was also supported by the binding energy parameters calculated by molecular docking. Moreover, the experimentally determined G⁰ nicely correlated with those determined by molecular docking and MD-simulation. Further, computational results clearly showed that the binding of HP with BSA in the subdomains IB and IIA. Page(s): 175-187

A comparative 2D QSAR study on a series of hydroxamic acid-based histone deacetylase inhibitors vis-à-vis comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA)

Sun, 01 Jun 2014 00:00:00 GMT

Title: A comparative 2D QSAR study on a series of hydroxamic acid-based histone deacetylase inhibitors vis-à-vis comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) Authors: Bajpai, Anubha; Agarwal, Neeraj; Gupta, Satya P Abstract: A quantitative structure-activity relationship (QSAR) study was performed on a series of indole amide analogues reported by Dai et al. [Bioorg Med Chem Lett (2003), 13, 1897-1901] to act as histone deacetylase (HDAC) inhibitors. The multiple regression analysis (MRA) revealed a model showing the significant dependence of the activity on molar refractivity (MR) and global topological charge index (GTCI) of the compounds, suggesting that inhibition of the HDAC by this series of compounds might involve the dispersion interaction with the receptor, where charge transfer between pairs of atoms might greatly help to polarize the molecule. The MRA results were then compared with those obtained by Guo et al. [Bioorg Med Chem (2005), 13, 5424-5434] by comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). It was found that MRA gave as good results and had as good predictive ability as CoMFA and CoMSIA. Besides, MRA was also able to throw the light on the physicochemical properties of the molecules that were involved in drug-receptor interactions, while CoMFA and CoMSIA could not. The dispersion interaction between the molecule and the active site of the receptor is suggested to be the main interaction. Page(s): 244-252

Some critical aspects of FT-IR, TGA, powder XRD, EDAX and SEM studies of calcium oxalate urinary calculi

Sun, 01 Jun 2014 00:00:00 GMT

Title: Some critical aspects of FT-IR, TGA, powder XRD, EDAX and SEM studies of calcium oxalate urinary calculi Authors: Joshi, Vimal S; Vasant, Sonal R; Bhatt, J G; Joshi, Mihir J Abstract: Urinary calculi constitute one of the oldest afflictions of humans as well as animals, which are occurring globally. The calculi vary in shape, size and composition, which influence their clinical course. They are usually of the mixed-type with varying percentages of the ingredients. In medical management of urinary calculi, either the nature of calculi is to be known or the exact composition of calculi is required. In the present study, two selected calculi were recovered after surgery from two different patients for detailed examination and investigated by using Fourier-Transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA), powder X-ray diffraction (XRD), scanning electron microscopy and energy dispersive analysis of X-rays (EDAX) techniques. The study demonstrated that the nature of urinary calculi and presence of major phase in mixed calculi could be identified by FT-IR, TGA and powder XRD, however, the exact content of various elements could be found by EDAX only. Page(s): 237-243

Fibrinogen, bFGF and VEGF levels during antibiotic therapy in gynecologic cancer: A preliminary report

Sun, 01 Jun 2014 00:00:00 GMT

Title: Fibrinogen, bFGF and VEGF levels during antibiotic therapy in gynecologic cancer: A preliminary report Authors: Palatyńska-Ulatowska, Aleksandra; Michalska, Marta; Łazarenkow, Andrzej; Nawrot-Modranka, Jolanta; Mirowski, Marek; Palatyński, Antoni; Jesionek-Kupnicka, Dorota Abstract: The role of angiogenesis in the development of neoplasia has been identified and characterized. However, anti-angiogenic therapeutic intervention still requires more evidence to become recognized and successful. The aim of this study was to evaluate levels of selected proangiogenic factors, such as fibrinogen, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in serum of patients with the gynecologic cancer on the first, third and sixth day of antibiotic therapy, routinely administered as a perioperative treatment. In addition, serum concentrations of γ-γ dimers and α-polymers of cross-linked fibrin structure and the degree of bFGF binding with the fibrin network were investigated. Immunohistochemistry staining of the excised tumor tissue was also performed. We observed higher levels of bFGF, VEGF, as well as fibrinogen in patients with gynecologic malignancy, as compared to healthy women. In cancer patients, the concentration of α-polymers and γ-γ dimers of fibrin network increased. Further only γ-γ dimers fraction of fibrin was found to bind to bFGF. Immunohistochemical analysis indicated the presence of bFGF in an excised tumor tissue. In conclusion, the decrease of proangiogenic bFGF and fibrinogen levels in a clinical trial of gynecologic patients may confirm anti-angiogenic properties of selected antibiotic therapy. Page(s): 230-236