Dr. Faez Iqbal Khan is an Assistant Professor of the Department of Biological Sciences at the Xi’an Jiaotong-Liverpool University. Dr. Khan received his Ph.D. degree in Computational Chemistry (Bioinformatics) from Durban University of Technology, South Africa. He received his B.Sc. and M.Sc. degrees in Biomedical Science and Bioinformatics. Dr. Khan carried out further research work and teaching at Rhodes University (South Africa), South China University of Technology, and the University of Electronic Science and Technology of China. His primary research focuses on Protein engineering, Protein folding, drug design and Protein dynamics. Dr. Khan established wide-ranging collaborations with BRICS countries and mentored several postgraduate students. He has authored over 70 publications in international peer-reviewed journals which are well cited. Address: Durban, South Africa
Objective: Neuropathic pain (NP) is defined as pain associated with damage or permanent alteratio... more Objective: Neuropathic pain (NP) is defined as pain associated with damage or permanent alteration of the peripheral or central nervous system. Current drug treatment for the management of neuropathic pain associated with various adverse effects. The present study was designed to investigate the combined effect of acamprosate and baclofen in experimental model of peripheral neuropathic pain in wistar rats. Material and methods: Neuropathic pain was induced by Chronic constriction injured (CCI) of sciatic nerve in rats. Acamprosate (100 and 200 mg/kg p.o) and baclofen (10 and 20 mg/kg p.o) was given in different groups for 14 days starting on 7th day post sciatic nerve ligation. Further combination of acamprosate(100 mg/kg p.o) and baclofen (10 mg/kg p.o) was also given to one group. On 1th, 3rd, 7th, 14thand 21stday behavioral parameters like mechanical allodynia and thermal hyperalgesia were assessed. Then animals were sacrificed on 22nd day and biochemical parameters (GSH, LPO, ca...
Various spectroscopic techniques involving fluorescence spectroscopy, circular dichroism (CD), an... more Various spectroscopic techniques involving fluorescence spectroscopy, circular dichroism (CD), and computational approaches were used to elucidate the molecular aspects of interaction between the antiepileptic drug topiramate and the multifunctional transport protein bovine serum albumin (BSA) under physiological conditions. Topiramate quenched BSA fluorescence in a static quenching mode, according to the Stern‐Volmer quenching constant (Ksv) data derived from fluorescence spectroscopy for the topiramate‐BSA complex. The binding constant was also used to calculate the binding affinity for the topiramate‐BSA interaction. Fluorescence and circular dichroism experiments demonstrate that the protein's tertiary structure is affected by the microenvironmental alterations generated by topiramate binding to BSA. To establish the exact binding site, interacting residues, and interaction forces involved in the binding of topiramate to BSA, molecular modeling and simulation approaches were...
Journal of Biomolecular Structure and Dynamics, 2021
Abstract The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a colossal l... more Abstract The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a colossal loss to human health and lives and has deeply impacted socio-economic growth. Remarkable efforts have been made by the scientific community in containing the virus by successful development of vaccines and diagnostic kits. Initiatives towards drug repurposing and discovery have also been undertaken. In this study, we compiled the known natural anti-viral compounds using text mining of the literature and examined them against four major structural proteins of SARS-CoV-2, namely, spike (S) protein, nucleocapsid (N) protein, membrane (M) protein and envelope (E) protein. Following computational approaches, we identified fangchinoline and versicolactone C as the compounds to exhibit strong binding to the target proteins and causing structural deformation of three structural proteins (N, S and M). We recommend the inhibitory effects of these compounds from our study should be experimentally validated against SARS-CoV-2. Communicated by Ramaswamy H. Sarma
N-formyl pyrazoline derivatives (3a-3l) were designed and synthesized via Michael addition reacti... more N-formyl pyrazoline derivatives (3a-3l) were designed and synthesized via Michael addition reaction through cyclization of chalcones with hydrazine hydrate in presence of formic acid. The structural elucidation of N-formyl pyrazoline derivatives was carried out by various spectroscopic techniques such as 1H, 13C NMR, FT-IR, UV-visible spectroscopy, mass spectrometry and elemental analysis. Anticancer activity of the pyrazoline derivatives (3a-3l) was evaluated against human lung cancer (A549), fibrosarcoma cell lines (HT1080) and human primary normal lung cells (HFL-1) by MTT assay. The results of anticancer activity showed that potent analogs 3b and 3d exhibited promising activity against A549 (IC50 = 12.47 ± 1.08 and 14.46 ± 2.76 µM) and HT1080 (IC50 = 11.40 ± 0.66 and 23.74 ± 13.30 µM) but low toxic against the HFL-1 (IC50 = 116.47 ± 43.38 and 152.36 ± 22.18 µM). The anticancer activity of potent derivatives (3b and 3d) against A549 cancer cell line was further confirmed by flow cytometry based approach. DNA binding interactions of the pyrazoline derivatives 3b and 3d have been carried out with calf thymus DNA (Ct-DNA) using absorption, fluorescence and viscosity measurements, circular dichroism and cyclic voltammetry. Antioxidant potential of N-formyl pyrazoline derivatives (3a-3l) has been also estimated through DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical and H2O2. Results revealed that all the compounds exhibited significant antioxidant activity. In silico molecular modelling and ADMET properties of pyrazoline derivatives were also studied using PyRx software against topoisomerase II receptor with PDB ID: 1ZXM to explore their best hits. MD simulation of 3b and 3d was also carried out with topoisomerase II for structure-function correlation in a protein. HuTopoII inhibitory activity of the analogs (3a-3l) was examined by relaxation assay at varying concentrations 100-1000 µM.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2021
A photoactivatable near-infrared fluorescent protein (NIR-FP) PAiRFP1 has been developed by 15 am... more A photoactivatable near-infrared fluorescent protein (NIR-FP) PAiRFP1 has been developed by 15 amino acid substitutions in its nonfluorescent template Agp2. In our previous communication, we investigated the role of three amino acids in PHY domain distal from BV molecule. The impact of the twelve amino acids in GAF domain, especially five residues near BV-binding pocket is unclear. In this paper, PCR based reverse mutagenesis, spectroscopic methods, molecular modelling and simulations have been employed to explore the roles of these substitutions during the molecular evolution of PAiRFP1. It was found that the residue L163 is important for protein folding in PAiRFP1. The residues F244 and C280 exerted remarkable effects on molar extinction coefficient, NIR fluorescence quantum yield, molecular brightness, fluorescence fold, and dark recovery rate. The residues F244 and V276 modulate the maximum absorption and emission peak position. The reverse mutant L168M exhibited a higher fluorescence fold than PAiRFP1. Additionally, the reverse mutants V203A, V294E, S218G and D127G possessed better spectral properties than PAiRFP1. This study is important for the rational design of a better BphP-based photoactivatable NIR-FPs.
Leprosy is an infectious disease caused by non-cultivable bacteria Mycobacterium leprae. Ridley a... more Leprosy is an infectious disease caused by non-cultivable bacteria Mycobacterium leprae. Ridley and Jopling classified the disease into five polar forms, Tuberculoid (TT) and Lepromatous (LL), in between two forms of the disease Borderline tuberculoid (BT), Borderline (BB) and Borderline lepromatous (BL) are laid. The tuberculoid type (BT/TT) leprosy patients show good recall of cell-mediated immune (CMI) response and Th1 type of immune response, while lepromatous leprosy (LL) patients show defect in cell-mediated immunity to the causative agent and Th2 type of immune response. Due to distinct clinical and immunological spectra of the disease, leprosy attracted immunologists to consider an ideal model for the study of deregulations of various immune reactions. Recent studies show that Tregs, Th3 (TGF-β, IL-10), IL-35 producing Treg immune response associated with the immune suppressive environment, survival of bugs and associated with lepromatous leprosy. IL-17 producing Th17 immune response associated with tuberculoid leprosy and play protective role. γδ T cells also increased from tuberculoid to lepromatous pole of leprosy. In this review, we will discuss the role of various subtypes of T-cell and their cytokines in the pathogenesis of leprosy.
International Journal of Biological Macromolecules, 2016
Cyanobacterial phycoerythrin (αC-PE) from Phormidium tenue exists in two natural forms named as f... more Cyanobacterial phycoerythrin (αC-PE) from Phormidium tenue exists in two natural forms named as full length (FL-αC-PE) and truncated (Tr-αC-PE). FL-αC-PE and Tr-αC-PE are produced when cyanobacterium is grown in the optimal medium and nutrient deficient medium, respectively. Despite of N-terminal deletion, both proteins show similar spectroscopic properties. In this study, different optical properties of these two natural variants of C-PE were measured in the pH range 1.0-12.0 (1.0≤pH≤12.0). It was observed that: (i) their absorption, fluorescence and CD spectra remain unchanged within the range adjacent to neutral pH, 5.5-8.75, (ii) at pH values higher than 8.75 and lower than 5.5 their absorption, fluorescence and CD spectral signatures are changed significantly, and (iii) emission spectra of the covalently linked tetrapyrrole chromophores and Trp residue are perturbed at extreme pH values in the range 8.75<pH<5.5. Refolding experiments further suggest that pH-induced denaturation of both forms of C-PE is reversible in the pH range 2.5-11.0, but irreversible beyond this range on both sides of pH extremes. The pH-induced denaturation of both the full length and truncated αC-PEs follows a two-state mechanism.
Objective: Neuropathic pain (NP) is defined as pain associated with damage or permanent alteratio... more Objective: Neuropathic pain (NP) is defined as pain associated with damage or permanent alteration of the peripheral or central nervous system. Current drug treatment for the management of neuropathic pain associated with various adverse effects. The present study was designed to investigate the combined effect of acamprosate and baclofen in experimental model of peripheral neuropathic pain in wistar rats. Material and methods: Neuropathic pain was induced by Chronic constriction injured (CCI) of sciatic nerve in rats. Acamprosate (100 and 200 mg/kg p.o) and baclofen (10 and 20 mg/kg p.o) was given in different groups for 14 days starting on 7th day post sciatic nerve ligation. Further combination of acamprosate(100 mg/kg p.o) and baclofen (10 mg/kg p.o) was also given to one group. On 1th, 3rd, 7th, 14thand 21stday behavioral parameters like mechanical allodynia and thermal hyperalgesia were assessed. Then animals were sacrificed on 22nd day and biochemical parameters (GSH, LPO, ca...
Various spectroscopic techniques involving fluorescence spectroscopy, circular dichroism (CD), an... more Various spectroscopic techniques involving fluorescence spectroscopy, circular dichroism (CD), and computational approaches were used to elucidate the molecular aspects of interaction between the antiepileptic drug topiramate and the multifunctional transport protein bovine serum albumin (BSA) under physiological conditions. Topiramate quenched BSA fluorescence in a static quenching mode, according to the Stern‐Volmer quenching constant (Ksv) data derived from fluorescence spectroscopy for the topiramate‐BSA complex. The binding constant was also used to calculate the binding affinity for the topiramate‐BSA interaction. Fluorescence and circular dichroism experiments demonstrate that the protein's tertiary structure is affected by the microenvironmental alterations generated by topiramate binding to BSA. To establish the exact binding site, interacting residues, and interaction forces involved in the binding of topiramate to BSA, molecular modeling and simulation approaches were...
Journal of Biomolecular Structure and Dynamics, 2021
Abstract The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a colossal l... more Abstract The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a colossal loss to human health and lives and has deeply impacted socio-economic growth. Remarkable efforts have been made by the scientific community in containing the virus by successful development of vaccines and diagnostic kits. Initiatives towards drug repurposing and discovery have also been undertaken. In this study, we compiled the known natural anti-viral compounds using text mining of the literature and examined them against four major structural proteins of SARS-CoV-2, namely, spike (S) protein, nucleocapsid (N) protein, membrane (M) protein and envelope (E) protein. Following computational approaches, we identified fangchinoline and versicolactone C as the compounds to exhibit strong binding to the target proteins and causing structural deformation of three structural proteins (N, S and M). We recommend the inhibitory effects of these compounds from our study should be experimentally validated against SARS-CoV-2. Communicated by Ramaswamy H. Sarma
N-formyl pyrazoline derivatives (3a-3l) were designed and synthesized via Michael addition reacti... more N-formyl pyrazoline derivatives (3a-3l) were designed and synthesized via Michael addition reaction through cyclization of chalcones with hydrazine hydrate in presence of formic acid. The structural elucidation of N-formyl pyrazoline derivatives was carried out by various spectroscopic techniques such as 1H, 13C NMR, FT-IR, UV-visible spectroscopy, mass spectrometry and elemental analysis. Anticancer activity of the pyrazoline derivatives (3a-3l) was evaluated against human lung cancer (A549), fibrosarcoma cell lines (HT1080) and human primary normal lung cells (HFL-1) by MTT assay. The results of anticancer activity showed that potent analogs 3b and 3d exhibited promising activity against A549 (IC50 = 12.47 ± 1.08 and 14.46 ± 2.76 µM) and HT1080 (IC50 = 11.40 ± 0.66 and 23.74 ± 13.30 µM) but low toxic against the HFL-1 (IC50 = 116.47 ± 43.38 and 152.36 ± 22.18 µM). The anticancer activity of potent derivatives (3b and 3d) against A549 cancer cell line was further confirmed by flow cytometry based approach. DNA binding interactions of the pyrazoline derivatives 3b and 3d have been carried out with calf thymus DNA (Ct-DNA) using absorption, fluorescence and viscosity measurements, circular dichroism and cyclic voltammetry. Antioxidant potential of N-formyl pyrazoline derivatives (3a-3l) has been also estimated through DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical and H2O2. Results revealed that all the compounds exhibited significant antioxidant activity. In silico molecular modelling and ADMET properties of pyrazoline derivatives were also studied using PyRx software against topoisomerase II receptor with PDB ID: 1ZXM to explore their best hits. MD simulation of 3b and 3d was also carried out with topoisomerase II for structure-function correlation in a protein. HuTopoII inhibitory activity of the analogs (3a-3l) was examined by relaxation assay at varying concentrations 100-1000 µM.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2021
A photoactivatable near-infrared fluorescent protein (NIR-FP) PAiRFP1 has been developed by 15 am... more A photoactivatable near-infrared fluorescent protein (NIR-FP) PAiRFP1 has been developed by 15 amino acid substitutions in its nonfluorescent template Agp2. In our previous communication, we investigated the role of three amino acids in PHY domain distal from BV molecule. The impact of the twelve amino acids in GAF domain, especially five residues near BV-binding pocket is unclear. In this paper, PCR based reverse mutagenesis, spectroscopic methods, molecular modelling and simulations have been employed to explore the roles of these substitutions during the molecular evolution of PAiRFP1. It was found that the residue L163 is important for protein folding in PAiRFP1. The residues F244 and C280 exerted remarkable effects on molar extinction coefficient, NIR fluorescence quantum yield, molecular brightness, fluorescence fold, and dark recovery rate. The residues F244 and V276 modulate the maximum absorption and emission peak position. The reverse mutant L168M exhibited a higher fluorescence fold than PAiRFP1. Additionally, the reverse mutants V203A, V294E, S218G and D127G possessed better spectral properties than PAiRFP1. This study is important for the rational design of a better BphP-based photoactivatable NIR-FPs.
Leprosy is an infectious disease caused by non-cultivable bacteria Mycobacterium leprae. Ridley a... more Leprosy is an infectious disease caused by non-cultivable bacteria Mycobacterium leprae. Ridley and Jopling classified the disease into five polar forms, Tuberculoid (TT) and Lepromatous (LL), in between two forms of the disease Borderline tuberculoid (BT), Borderline (BB) and Borderline lepromatous (BL) are laid. The tuberculoid type (BT/TT) leprosy patients show good recall of cell-mediated immune (CMI) response and Th1 type of immune response, while lepromatous leprosy (LL) patients show defect in cell-mediated immunity to the causative agent and Th2 type of immune response. Due to distinct clinical and immunological spectra of the disease, leprosy attracted immunologists to consider an ideal model for the study of deregulations of various immune reactions. Recent studies show that Tregs, Th3 (TGF-β, IL-10), IL-35 producing Treg immune response associated with the immune suppressive environment, survival of bugs and associated with lepromatous leprosy. IL-17 producing Th17 immune response associated with tuberculoid leprosy and play protective role. γδ T cells also increased from tuberculoid to lepromatous pole of leprosy. In this review, we will discuss the role of various subtypes of T-cell and their cytokines in the pathogenesis of leprosy.
International Journal of Biological Macromolecules, 2016
Cyanobacterial phycoerythrin (αC-PE) from Phormidium tenue exists in two natural forms named as f... more Cyanobacterial phycoerythrin (αC-PE) from Phormidium tenue exists in two natural forms named as full length (FL-αC-PE) and truncated (Tr-αC-PE). FL-αC-PE and Tr-αC-PE are produced when cyanobacterium is grown in the optimal medium and nutrient deficient medium, respectively. Despite of N-terminal deletion, both proteins show similar spectroscopic properties. In this study, different optical properties of these two natural variants of C-PE were measured in the pH range 1.0-12.0 (1.0≤pH≤12.0). It was observed that: (i) their absorption, fluorescence and CD spectra remain unchanged within the range adjacent to neutral pH, 5.5-8.75, (ii) at pH values higher than 8.75 and lower than 5.5 their absorption, fluorescence and CD spectral signatures are changed significantly, and (iii) emission spectra of the covalently linked tetrapyrrole chromophores and Trp residue are perturbed at extreme pH values in the range 8.75<pH<5.5. Refolding experiments further suggest that pH-induced denaturation of both forms of C-PE is reversible in the pH range 2.5-11.0, but irreversible beyond this range on both sides of pH extremes. The pH-induced denaturation of both the full length and truncated αC-PEs follows a two-state mechanism.
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Papers by Faez I Khan