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In Silico Study of Human Gap Junction Beta-2 Protein by Homology Modeling
Shehzadi, Abida,Masood, Khalid Korea Genome Organization 2010 Genomics & informatics Vol.8 No.2
Asp66his, Asp54Lys, and Asp50Asn are mutations in connexin 26 that are observed in the clinic and give rise to autosomal dominant syndromes. They are the result of point mutations in the human gap junction ${\beta}-2$ gene. In order to investigate the structural mechanism of Bart-Pumphrey Syndrome, Keratitis-Ichthyosis-Deafness Syndrome, and Vohwinkel Syndrome, homology modeling was carried out. Asp66 has direct contact with Asn62 by two hydrogen bonds in the wild-type protein, and in Asp66His, the biggest change observed is a tremendous energy increase caused by hydrogen bond breakage to Asn62. Shifts in the side chain and new hydrogen bond formation are observed for Lys54 compared to the wild-type protein (Asn54) and result in closer contact to Val84. Asp50Asn causes a significant decrease in bond energy, and residual charge reversal repels the ion and metabolites and, hence, inhibits their transportation. Such perturbations are likely to be a factor contributing to abnormal functioning of ion channels, resulting cell death and disease.
Shehzadi Nazia Neelam,Yi Chul-Young,Kim Ki-Hwan,Jang Jaeuk,Hwang Ui-Jung,Kim Yunho,Kim In Jung,Seong Young Min 한국물리학회 2021 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.78 No.6
The purpose of this study was to check the applicability of radiophotoluminescent glass dosimeter (RPLGD) for in vivo dosimetry in external photon beams radiotherapy. The entrance dose measurements were performed. The influence of beam set-up parameters on the entrance dose was investigated using the RPLGDs. In this study, the RPLGD and 6-MV photon beam produced by a linear accelerator were used. The entrance dose calibration factors of the RPLGDs and beam energy and geometry-dependent correction factors were measured using a water phantom. For a correction factor related to the irradiation set-up, Monte Carlo (MC) simulation was performed. The entrance dose verification was performed on an Alderson Rando phantom during 64 single beam irradiations using different beam set-up. One RPLGD was attached on surface during a single beam irradiation for delivery of clinically planned dose. Additionally, during 50 irradiations, one RPLGD was placed directly inside the Alderson Rando phantom at different points in the beam path to verify the dose delivery. The mean ratio of the measured entrance dose using RPLGD on the surface of the phantom to the expected dose which was calculated by treatment planning system was equal to 1.001 ± 0.030. The mean ratio of the dose measured using RPLGDs inside the Alderson Rando phantom to the expected dose was equal to 1.019 ± 0.019. This study concludes that the RPLGD is suitable for in vivo dosimetry in external photon beam radiotherapy for dose verification within ± 5% at the clinically acceptable level.
Shehzadi, Syeda Aaliya,Khan, Imtiaz,Saeed, Aamer,Larik, Fayaz Ali,Channar, Pervaiz Ali,Hassan, Mubashir,Raza, Hussain,Abbas, Qamar,Seo, Sung-Yum Academic Press 2019 Bioorganic chemistry Vol.84 No.-
<P><B>Abstract</B></P> <P>An efficient one-pot four-component strategy involving aldehydes, amines, alkynes and isothiocyanates has been developed to access a novel series of thiazolidine-2-imines (<B>5a-x</B>). This process operates under the action of a cooperative catalysis composed of Cu(I) and Zn(II) delivering the desired five-membered heterocyclic compounds in good to excellent yields. Notably, this transformation avoids the use of pre-formed imines or propargylamines and proceeds <I>via</I> an intramolecular 5-<I>exo-dig</I> hydrothiolation reaction of the <I>in situ</I> formed propargyl thiourea. Furthermore, the biological application of these motifs was demonstrated in terms of their strong acetylcholinesterase (AChE) inhibitory activity where compound <B>5s</B> was identified as the lead AChE inhibitor with an IC<SUB>50</SUB> value of 0.0023 ± 0.0002 μM, 88-folds stronger inhibition than standard drug (neostigmine methyl sulphate; IC<SUB>50</SUB> = 0.203 ± 0.004 μM). Molecular docking analysis reinforced the <I>in vitro</I> biological activity results revealing the formation of several useful interactions of the potent lead with amino acid residues in the active site of the enzyme.</P> <P><B>Highlights</B></P> <P> <UL> <LI> One-pot four component methodology was developed under Cu/Zn dual catalysis. </LI> <LI> A diverse range of thiazolidin-2-imines was prepared in excellent yields. </LI> <LI> Good functional group tolerance and broad substrate scope were explored. </LI> <LI> Potent inhibitors (<B>5b</B>, <B>5i</B>, <B>5s</B>, <B>5t</B>) of acetylcholinesterase were identified. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
In Silico Study of Human Gap Junction Beta-2 Protein by Homology Modeling
Abida Shehzadi,Khalid Masood 한국유전체학회 2010 Genomics & informatics Vol.8 No.2
Asp66his, Asp54Lys, and Asp50Asn are mutations in connexin 26 that are observed in the clinic and give rise to autosomal dominant syndromes. They are the result of point mutations in the human gap junction β-2 gene. In order to investigate the structural mechanism of Bart-Pumphrey Syndrome, Keratitis-Ichthyosis-Deafness Syndrome, and Vohwinkel Syndrome, homology modeling was carried out. Asp66 has direct contact with Asn62 by two hydrogen bonds in the wild-type protein, and in Asp66His, the biggest change observed is a tremendous energy increase caused by hydrogen bond breakage to Asn62. Shifts in the side chain and new hydrogen bond formation are observed for Lys54 compared to the wild-type protein (Asn54) and result in closer contact to Val84. Asp50Asn causes a significant decrease in bond energy, and residual charge reversal repels the ion and metabolites and, hence, inhibits their transportation. Such perturbations are likely to be a factor contributing to abnormal functioning of ion channels, resulting cell death and disease.
Determination of Bergenin in Different Parts of Bergenia ciliata using a Validated RP-HPLC Method
Ejaz Ali,Khalid Hussain,Nadeem Irfan Bukhari,Najma Arshad,Amjad Hussain,Nasir Abbas,Sohail Arshad,Sajida Parveen,Naureen Shehzadi,Shaista Qamar,Abida Qamar 한국생약학회 2021 Natural Product Sciences Vol.27 No.1
Bergenia ciliata (Family: Saxifragaceae) is a folklore remedy for the treatment of various ailments in Asian countries. Bergenin (1) has been isolated as an active constituent in many studies, however, the amount of bergenin has not been determined in all parts of the plant. A simple RP-HPLC method was developed to determine the amount of bergenin in methanol extracts of leaves, rhizomes and roots of the plant. Separation was achieved on an Agilent Eclipse XDB-C18 column maintained at 25 oC using isocratic solvent system (water: methanol: acetic acid; 62.5:37:0.5 v/v/v) adjusted at pH 2 0 at a flow rate of 1.0 mL/min. and detected at 275 nm. Correlation coefficient (0.9952) showed linearity of concentration (5-200 μg/mL) and response. The values of LOD (0.00947 μg/mL) and LOQ (0.02869 μg/mL) indicated that method was sensitive. The recovery of bergenin was 99.99-100% indicating accuracy of method. The methanol extract of rhizomes contained higher amount of bergenin (19.4%) than roots (9.2%) and leaves (6.9%). It is concluded that methanol extract of rhizomes is a better source of bergenin than other parts of the plant. The findings are useful for standardization of bergenin containing extracts and herbal preparations.