https://vital.seals.ac.za/vital/access/manager/Index ${session.getAttribute("locale")} 5 https://vital.seals.ac.za/vital/access/manager/Repository/vital:42919 Wed 26 May 2021 15:20:13 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65368 Wed 26 Jul 2023 10:33:21 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65367 Wed 26 Jul 2023 09:58:27 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65774 Wed 26 Jul 2023 09:16:33 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65767 Wed 26 Jul 2023 09:09:34 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45265 Wed 24 Nov 2021 15:28:04 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:50127 Wed 20 Jul 2022 10:18:38 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:42922 Wed 19 May 2021 10:55:23 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45195 Wed 16 Mar 2022 16:08:28 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:29198 Wed 15 Mar 2023 15:47:55 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:30044 Wed 15 Mar 2023 13:14:02 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:29167 Wed 15 Mar 2023 11:50:00 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28395 Wed 12 May 2021 23:59:53 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28075 Wed 12 May 2021 23:29:16 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:38243 Wed 12 May 2021 20:52:22 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28296 Wed 12 May 2021 20:04:41 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:37810 Wed 12 May 2021 19:28:59 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:34273 Wed 12 May 2021 19:20:56 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:34287 Wed 12 May 2021 19:13:05 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:29112 Wed 12 May 2021 18:53:14 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28433 Wed 12 May 2021 17:54:50 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:35531 Wed 12 May 2021 17:18:32 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:30574 Wed 12 May 2021 17:08:20 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:30011 Wed 12 May 2021 16:12:08 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:30810 Wed 12 May 2021 15:50:08 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41028 Wed 12 May 2021 15:08:19 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41155 Wed 12 May 2021 15:03:14 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41493 Wed 12 May 2021 15:00:41 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:42918 Wed 12 May 2021 14:59:28 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:42950 Wed 12 May 2021 14:46:17 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:42952 Wed 12 May 2021 14:42:52 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41051 Wed 12 May 2021 14:34:28 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41458 0.5, suggesting that further development of the assay format to identify GEF and GAP inhibitors may be feasible. In the case of the colorimetric assay, robust signals could be detected and the assay was useful for detecting the activation status of ARF1. However, although the activation of ARF1 by the Sec7 domains of the BIG1 and ARNO was detectable, signals were not robust enough to employ in screening campaigns.]]> Wed 12 May 2021 14:25:48 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41142 Wed 12 May 2021 14:21:50 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41443 Wed 12 May 2021 14:21:40 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41029 Wed 12 May 2021 14:19:55 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41122 Wed 12 May 2021 14:09:28 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41125 Wed 12 May 2021 14:07:40 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41156 Wed 12 May 2021 14:04:32 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:42944 Wed 12 May 2021 14:03:03 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41108 Wed 12 May 2021 13:56:41 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41440 Wed 12 May 2021 13:53:32 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:42898 Wed 12 May 2021 13:51:19 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41027 Wed 12 May 2021 13:50:39 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41470 Wed 12 May 2021 13:50:01 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:42951 Wed 12 May 2021 13:46:56 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65760 Wed 12 Jul 2023 17:20:28 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65724 Wed 12 Jul 2023 09:37:51 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65723 Wed 12 Jul 2023 09:31:05 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65721 Wed 12 Jul 2023 09:19:30 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65719 Wed 12 Jul 2023 09:10:21 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:36758 Wed 12 Apr 2023 09:51:36 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45073 Wed 06 Jul 2022 08:47:38 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41030 Wed 05 Apr 2023 11:50:25 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41018 Tue 30 Nov 2021 08:34:14 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65777 Tue 30 Jan 2024 21:24:18 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56806 Tue 27 Sep 2022 09:15:51 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:49985 Tue 19 Jul 2022 09:37:26 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65378 Tue 16 Jan 2024 14:38:10 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65377 Tue 16 Jan 2024 14:30:59 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28061 Tue 15 Aug 2023 11:05:18 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:27230 Thu 22 Jul 2021 14:38:29 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:50170 Thu 21 Apr 2022 17:19:02 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:50169 Thu 21 Apr 2022 17:09:08 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28523 Thu 13 May 2021 07:20:26 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:34282 Thu 13 May 2021 07:18:46 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:29165 Thu 13 May 2021 07:11:47 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:27449 Thu 13 May 2021 06:54:36 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:29539 Thu 13 May 2021 06:24:12 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:34035 Thu 13 May 2021 05:52:57 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28406 Thu 13 May 2021 05:46:15 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:37825 Thu 13 May 2021 04:44:54 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:27820 Thu 13 May 2021 04:39:10 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:38089 3000 cases and controls) are required. Macrophage migration inhibitory factor (MIF) is a cytokine that is important in both innate and adaptive immunity that has been shown to play a role in T. brucei pathogenicity using murine models. A total of 27 missense SNVs were modelled using homology modelling to create MIF protein mutants that were investigated using in silico effect prediction tools, molecular dynamics (MD), Principal Component Analysis (PCA), and Dynamic Residue Network (DRN) analysis. Our results demonstrate that mutations P2Q, I5M, P16Q, L23F, T24S, T31I, Y37H, H41P, M48V, P44L, G52C, S54R, I65M, I68T, S75F, N106S, and T113S caused significant conformational changes. Further, DRN analysis showed that residues P2, T31, Y37, G52, I65, I68, S75, N106, and T113S are part of a similar local residue interaction network with functional significance. These results show how polymorphisms such as missense SNVs can affect protein conformation, dynamics, and function. Trypanosomes are auxotrophic for folates and pterins but require them for survival. They scavenge them from their hosts. PTR1 is a multifunctional enzyme that is unique to trypanosomatids that reduces both pterins and folates. In the presence of DHFR inhibitors, PTR1 is over-expressed thus providing an escape from the effects of DHFR inhibition. Both TbPTR1 and TbDHFR are pharmacologically and genetically validated drug targets. In this study 5742 compounds were screened using molecular docking, and 13 promising binding modes were further analysed using MD simulations. The trajectories were analysed using RMSD, Rg, RMSF, PCA, Essential Dynamics Analysis (EDA), Molecular Mechanics Poisson–Boltzmann surface area (MM-PBSA) binding free energy calculations, and DRN analysis. The computational screening approach allowed us to identify five of the compounds, named RUBi004, RUBi007, RUBi014, RUBi016 and RUBi018 that exhibited antitrypanosomal growth activities against trypanosomes in culture with IC50 values of 12.5 ± 4.8 μM, 32.4 ± 4.2 μM, 5.9 ± 1.4 μM, 28.2 ± 3.3 μM, and 9.7 ± 2.1 μM, respectively. Further when used in combination with WR99210 a known TbDHFR inhibitor RUBi004, RUBi007, RUBi014 and RUBi018 showed antagonism while RUBi016 showed an additive effect. These results indicate that the four compounds might be competing with TbDHFR while RUBi016 might be more specific for TbPTR1. These compounds provide scaffolds that can be further optimised to improve their potency and specificity. Lastly, using a systematic approach we derived CHARMM force-field parameters to accurately describe the TbrPDEB1 bi-metal catalytic center. For dynamics, we employed mixed bonded and non-bonded approach. We optimised the structure using a two-layer QM/MM ONIOM (B3LYP/6-31(g): UFF). The TbrPDEB1 bi-metallic center bonds, angles, and dihedrals were parameterized by fitting the energy profiles from Potential Energy Surface (PES) scans to the CHARMM potential energy function. The parameters were validated by means of MD simulations and analysed using RMSD, Rg, RMSF, hydrogen bonding, bond/angle/dihedral evaluations, EDA, PCA, and DRN analysis. The force-field parameters were able to accurately reproduce the geometry and dynamics of the TbrPDEB1 bi-metal catalytic center during MD simulations. Molecular docking was used to identify 6 potential hits, that inhibited trypanosome growth in vitro. The derived force-field parameters were used to simulate the 6 protein-ligand complexes with the aim of elucidating crucial protein-ligand residue interactions. Using the most potent ligand RUBi022 that had an IC50 of 14.96 μM we were able to identify key residue interactions that can be of use in in silico prediction of potential TbrPDEB1 inhibitors. Overall we demonstrate how bioinformatics tools can complement current disease eradication strategies. Future work will focus on identifying variants identified in Genome Wide Association Studies and partnering with wet labs to carry out further enzyme-ligand activity relationship studies, structure determination or characterisation of appropriate protein-ligand complexes by crystallography, and site specific mutation studies]]> Thu 13 May 2021 04:20:49 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:30022 Thu 13 May 2021 01:46:09 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28105 Thu 13 May 2021 01:32:49 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65780 Thu 13 Jul 2023 11:50:00 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65779 Thu 13 Jul 2023 11:36:46 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65778 Thu 13 Jul 2023 11:29:37 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65776 Thu 13 Jul 2023 10:47:08 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65775 100 kDa through ultracentrifugation. Mass spectrometry also detected the most abundant peak for all fucoidans to be around 700 Da (m/z). Extracted fucoidans inhibited the activity of α-glucosidase more strongly than the commercial anti-diabetic agent acarbose but were inactive on α-amylase. Fucoidans were also shown to be mixed inhibitors of α-glucosidase. Compellingly, fucoidans synergistically inhibited α-glucosidase in combination with the anti-diabetic agent acarbose, highlighting prospects for combination therapy. Finally, fucoidans demonstrated some anti-proliferative characteristics on HCT116 cancer cells by inhibiting their ability to adhere to the tissue culture plate matrix. Furthermore, some fucoidan extracts inhibited the migration of HCT116 cancer cells from 3D spheroids. Some of our fucoidan extracts also inhibited HCT116 colony formation, demonstrating inhibition of long-term cell survival. The E. maxima water extract also inhibited glucose uptake by HCT116 cells, thereby influencing the glycolytic flux. In conclusion, biologically active fucoidans were successfully extracted from South African brown seaweeds. These fucoidans demonstrated anti-diabetic and anti-cancer properties, revealing their relevance as potential drugs for these diseases.]]> Thu 11 Jan 2024 18:08:05 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28128 Thu 09 Mar 2023 13:00:25 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28533 Thu 09 Mar 2023 09:44:15 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71940 Thu 04 Apr 2024 19:46:33 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71939 Thu 04 Apr 2024 19:46:24 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28216 Thu 01 Jun 2023 09:58:06 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:57234 Sun 09 Oct 2022 18:07:39 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71965 Sat 06 Apr 2024 15:13:22 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71964 Sat 06 Apr 2024 15:13:06 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28298 Sat 01 Jul 2023 12:28:13 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:34034 Mon 29 Nov 2021 19:44:55 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45240 Mon 15 Nov 2021 10:55:11 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45229 Mon 15 Nov 2021 10:05:51 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45227 Mon 15 Nov 2021 09:59:03 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28063 90%) sequence similarity between BSCOMT and human soluble COMT (HSCOMT). BSCOMT was partially purified to 7.78 fold, 1.65% yield and had a specific activity of 0.052 U/mg. It had pH and temperature optima of 8.5 and 40oC, respectively. The Km, Vmax, Kcat and Kcat/Km towards esculetin methylation were respectively 1.475±0.130 pM, 0.0353±0.001 pmol/ml/min, 1.748 x 10-2±5.0x10-4 min-1 and 1.18x10-2 M-1. min-1. HSCOMT was expressed in Escherichia coli BL21(DE3) which showed optimal activity for esculetin methylation at pH and temperature of 7.0 and 30°C, respectively. It was purified to 5.62 fold, 22.6% yield with a specific activity of 3.85 U/mg. HSCOMT kinetic plots, upon incubation of the reaction mixture at 30°C for 5 min before addition of SAM was hyperbolic with Km, Vmax, Kcat and Kcat/Km values of 1.79 pM, 0.412 pmol/ml/min, 2.08 min-1 and 1.165 M-1. min-1, respectively. AuNPs and AgNPs showed a concentration dependent inhibition of HSCOMT activity upon increasing the 5 min incubation time to 1 h. Interestingly, HSCOMT kinetics, with 1 h incubation at 30°C, showed a sigmoidal curve, as well as increased activity. Incubation of the reaction mixture in the presence of 60 pM AuNPs and/or AgNPs for 1 hreversed the observed sigmoidal to a hyperbolic curve, with kinetic parameters comparable to those of 5 min incubation. SDS-PAGE analyses of HSCOMT after the kinetic experiments showed the enzyme incubated for 5 min as a monomer, while that which was incubated for 1 h migrated substantially as dimer. However, the HSCOMT incubated for 1 h in the presence of 60 pM AuNPs and/or AgNPs migrated as a monomer. This indicated that the extension of the incubation period allowed the dimerization of HSCOMT, which exhibited sigmoidal kinetics and higher activity. The presence of NPs impeded the HSCOMT dimerization which decreased the activity. Varying the concentration of SAM suggested that SAM had an allosteric modulatory effect on HSCOMT. Absorption spectroscopy indicated adsorption of HSCOMT on the gold and silver NP surfaces and the formation of NPs-HSCOMT corona. Fluorescence spectroscopy showed that the interaction of HSCOMT with both gold and silver NPs was governed by a static quenching mechanism, implying the formation of a non-fluorescent fluorophore-NP complex at the ground state. Further fluorometric analyses indicated that both gold and silver NPs had contact with Trp143; that the interactions were spontaneous and were driven by electrostatic interactions. Fourier transform infrared spectroscopic studies showed the adsorption of HSCOMT of the NPs surfaces to cause relaxation of the enzyme’s B-sheet structures. Molecular docking studies indicated involvement of largely hydrophilic amino acids, with the interacting distances of less than 3.5A. These findings signify the potential of nanotechnology in the control of COMT catalytic activity for the management of the COMT-related disorders.]]> Mon 13 Mar 2023 14:31:23 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:50129 Mon 10 Oct 2022 08:54:24 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28065 Mon 05 Jun 2023 15:41:21 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45193 Fri 18 Feb 2022 12:59:54 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:57007 Fri 11 Nov 2022 08:55:16 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:28297 Fri 10 Mar 2023 12:46:15 SAST ]]>