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Munawar M.A.,University of Punjab | Lee Y.S.,University of Arizona | Rankin D.,University of Arizona | Munir J.,University of Punjab | And 4 more authors.
Bioorganic and Medicinal Chemistry | Year: 2015

A series of opioid and serotonin re-uptake inhibitors (SSRIs) bifunctional ligands have been designed, synthesized, and tested for their activities and efficacies at μ-, δ- and κ opioid receptors and SSRIs receptors. Most of the compounds showed high affinities for μ- and δ-opioid receptors and lower affinities for SSRIs and κ opioid receptors. A docking study on the μ-opioid receptor binding pocket has been carried out for ligands 3-11. The ligands 7 and 11 have displayed the highest binding profiles for the μ-opioid receptor binding site with ΔGbind (-12.14 kcal/mol) and Ki value (1.0 nM), and ΔGbind (-12.41 kcal/mol) and Ki value (0.4 nM), respectively. Ligand 3 was shown to have the potential of dual acting serotonin/norepinephrine re-uptake inhibitor (SNRI) antidepressant activity in addition to opioid activities, and thus could be used for the design of multifunctional ligands in the area of a novel approach for the treatment of pain and depression. © 2015 Elsevier Ltd. All rights reserved.

Mehr-Un-Nisa,University of Punjab | Munawar M.A.,University of Punjab | Chattha F.A.,University of Punjab | Kousar S.,University of Punjab | And 6 more authors.
Bioorganic and Medicinal Chemistry | Year: 2015

A novel serie of escitalopram triazoles (60-88) and a tetrazole (89) have been synthesized and subjected to a study to establish the inhibitory potential of these compounds toward acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Some selectivity in inhibition has been observed. The 4-chlorophenyl- (75, IC50, 6.71 ± 0.25 μM) and 2-methylphenyl- (70, IC50, 9.52 ± 0.23 μM) escitalopram triazole derivatives depicted high AChE inhibition, while 2-fluorophenyl- (76, IC50 = 4.52 ± 0.17 μM) and 4-fluorophenyl- (78, IC50 = 5.31 ± 0.43 μM) have found to be excellent BChE inhibitors. It has also been observed that ortho, meta and para substituted electron donating groups increase the inhibition, while electron withdrawing groups reduce the inhibition. Docking analyses of inhibitors with AChE have depicted the binding energies for 70 and 75 as ΔGbind -6.42 and -6.93 kcal/mol, respectively, while ligands 76 and 78 have shown the binding affinity ΔGbind -9.04 and -8.51 kcal/mol, respectively, for BChE. © 2015 Elsevier Ltd. All rights reserved.

Kaleem A.,Institute of Molecular science and Bioinformatics | Kaleem A.,The University of Lahore | Hoessli D.C.,Institute of Molecular science and Bioinformatics | Hoessli D.C.,University of Karachi | And 8 more authors.
Journal of Cellular Biochemistry | Year: 2011

The multifunctionality of proteins is dictated by post-translational modifications (PTMs) which involve the attachment of small functional groups such as phosphate and acetate, as well as carbohydrate moieties. These functional groups make the protein perform various functions in different environments. PTMs play a crucial role in memory and learning. Phosphorylation of synaptic proteins and transcription factors regulate the generation and storage of memory. Among these is the cAMP-regulated element binding protein CREB that regulates CRE containing genes like c-fos. Both phosphorylation and acetylation control the function of CREB as a transcription factor. CREB is also susceptible to O-GlcNAc modification, which inhibits its activity. O-GlcNAc modification occurs on the same or neighboring Ser/Thr residues akin to phosphorylation. An interplay between these modifications was shown to operate in nuclear and cytoplasmic proteins. In this study computational methods were utilized to predict different modification sites in CREB. These in silico results suggest that phosphorylation, OGlcNAc modification and acetylation modulate the transcriptional activity of CREB and thus dictate its contribution to synaptic plasticity. J. Cell. © 2010 Wiley-Liss, Inc.

Shakoori A.R.,University of Punjab | Hoessli D.C.,Institute of Molecular science and Bioinformatics | Nasir-Ud-Din,Institute of Molecular science and Bioinformatics | Nasir-Ud-Din,University of Karachi
Journal of Cellular Biochemistry | Year: 2013

Octamer DNA binding transcription factors play important roles in housekeeping and specific gene regulations. Octamer DNA binding transcription factor-1 (Oct-1), expressed ubiquitously, is a multifunctional molecule. The binding sites of Oct-1 are the promoters of H2B gene and the genes of snRNA, U2, U6, and 7SK, yet Oct-1 has been described as constitutively expressed transcription factor regulating the expression of housekeeping genes. Diverse tissue-specific genes regulations by Oct-1 include genes for interleukins (IL) 2, 3, 5; the granulocyte-macrophagal colony-stimulating factor, immunoglobulins α, β, Ly9; the endocrine-associated Pit-1 gene; the genes for gonadoliberin, prolactin, the thyroid transcription factor, and thyrotropin. The most interesting aspect of the gene regulations of Oct-1 includes both activation and inhibition of transcription. These opposite regulations of Oct-1 have been described through presence/absence of a post-translational modification (PTM) in its different domains. We propose a mechanism of interplay of different PTMs or presence/absence of PTMs in the different domains of Oct-1. We also suggest that the absence of phosphorylation and acetylation in G1 and S phases of the cell cycle is associated with interplay of methylation and O-GlcNAc modification. This interplay of O-GlcNAc modification with the phosphorylation and methylation with acetylation in POU sub-domain of Oct-1 may facilitate the formation of Oct-1-DNA complex, consequently activating H2B gene transcription. Whereas, in G2 and M phases these sites are occupied by phosphate resulting in inhibition of Oct-1-DNA complex formation leading to the suppression of H2B gene transcription. © 2012 Wiley Periodicals, Inc.

Iqbal Z.,Institute of Molecular science and Bioinformatics | Hoessli D.C.,Institute of Molecular science and Bioinformatics | Hoessli D.C.,University of Karachi | Qazi W.M.,The University of Lahore | And 4 more authors.
Journal of Cellular Biochemistry | Year: 2015

Several models that predict where post-translational modifications are likely to occur and formulate the corresponding association rules are available to analyze the functional potential of a protein sequence, but an algorithm incorporating the functional groups of the involved amino acids in the sequence analyses process is not yet available. In its previous version, MAPRes was utilized to investigate the influence of the surrounding amino acids of post- translationally and co-translationally modifiable sites. The MAPRes has been upgraded to take into account the different biophysical and biochemical properties of the amino acids that have the potential to influence different post- translational modifications (PTMs). In the present study, the upgraded version of MAPRes was implemented on phosphorylated Ser/Thr/Tyr data by considering the polarity and charge of the surrounding amino acids. The patterns mined by MAPRes incorporating structural information on polarity and charge of amino acids suggest distinct structure-function relationships for phosphorylated serines in a multifunctional protein such as the insulin-receptor substrate-1 (IRS-1) protein. The new version of MAPRes is freely available at http://www.imsb.edu.pk/Database.htm. J. Cell. Biochem. 116: 370-379, 2015. © 2014 Wiley Periodicals, Inc.

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