CHEMICAL INVESTIGATION OF NEEM LEAF GLYCOPROTEIN USED AS IMMUNOPROPHYLACTIC AGENT FOR TUMOR GROWTH RESTRICTION

Objective: Unique immune modulatory function of an aqueous preparation of neem leaf (NLP) in relation to cancer has already been reported. The objective of this present study is to find out the active component present in NLP.Methods: NLP was exposed to a gradient of temperature, pH and enzymes to use for mice immunization before tumor inoculation. Glycoprotein extracted from NLP was purified and analyzed by using Folin's phenol reagent, polyacrylamide gel electrophoresis, scanning electron microscopy and amino acid analysis. Carbohydrate moiety of this protein was analysed by GLC-MS. Immunogenicity was checked by ELISA and immunoblotting.Results: Exposure of NLP to adverse temperature and pH causes significant reduction in tumor growth restricting function of NLP. Treatment of NLP with proteolytic enzymes results abolition of the tumor growth restriction in mice. Biochemical assays indicated the presence of a glycoprotein in NLP, designated as neem leaf glycoprotein (NLGP) which appeared in non-denatured PAGE as a single band, and as three bands in SDS-PAGE having molecular weights 48 Kda, 24 Kda and 15 Kda. NLGP constitutes the carbohydrate moiety of about 33% consisting of arabinose, galactose and glucose. This glycoprotein consisted of seventeen amino acids of which nine were essential. Immunogenecity of this protein was defined by strong reaction of the ant-NLGP sera with NLGP by ELISA and immunoblot.Conclusion: Overall results demonstrated the immense potential of newly identified NLGP, present in NLP as an immunoprophylactic agent for tumor growth restriction.Â

Mixed-Ligand Assisted Direct Synthesis of Redox-Active UiO-66-(SH)2 Metal Organic Frameworks and Their Behavioural Pattern in Reductive and Oxidative Environments

Synthesis, storage, and characterization of thiol functionalized metal-organic frameworks (MOFs) is highly challenging. However, they continue to be of great interest due to their broad spectrum of applications. In this work, for the first time, a solid solution approach has been adopted to dilute the thiol content in UiO-66-(SH)2 [Universitetet i Oslo] MOF by terephthalic acid linker without influencing its topology. The solid dilution had an overall impact on the crystallinity, defects, porosity and particle size of the UiO-66-(SH)2 framework. This study has the potential to significantly influence the syntheses of nanoscale thiol functionalized MOF materials and their applications in photocatalysis, water purification and drug delivery. This work also incorporates the performance study of the mixed-linker thiol MOFs under reductive and oxidative conditions. The rate of para-nitrophenolate hydrogenation under reductive conditions were mainly governed by the stability of the mixed-linker MOFs as catalyst supports. Whereas, post synthetic oxidation (PSO) was used to produce sulfonic acid tagged mixed-linker UiO-66 frameworks to probe the behavioral pattern in oxidative conditions of the parent mixed-linker thiol MOFs. The mixed-linker strategy was critical in preventing the frameworks from losing their crystallinity and porosity, upon oxidation. Thus, this work also paves the way for a general strategy to impart stability to thiol tagged UiO-66 framework having wide ranging applications

Probing p300/CBP associated Factor (PCAF)-dependent pathways with a small molecule inhibitor

PCAF (KAT2B) belongs to the GNAT family of lysine acetyltransferases (KAT) and specifically acetylates the histone H3K9 residue and several nonhistone proteins. PCAF is also a transcriptional coactivator. Due to the lack of a PCAF KAT-specific small molecule inhibitor, the exclusive role of the acetyltransferase activity of PCAF is not well understood. Here, we report that a natural compound of the hydroxybenzoquinone class, embelin, specifically inhibits H3Lys9 acetylation in mice and inhibits recombinant PCAF-mediated acetylation with near complete specificity in vitro. Furthermore, using embelin, we have identified the gene networks that are regulated by PCAF during muscle differentiation, further highlighting the broader regulatory functions of PCAF in muscle differentiation in addition to the regulation via MyoD acetylation

Probing p300/CBP Associated Factor (PCAF)-Dependent Pathways with a Small Molecule Inhibitor

PCAF (KAT2B) belongs to the GNAT family of lysine acetyltransferases (KAT) and specifically acetylates the histone H3K9 residue and several nonhistone proteins. PCAF is also a transcriptional coactivator. Due to the lack of a PCAF KAT-specific small molecule inhibitor, the exclusive role of the acetyltransferase activity of PCAF is not well understood. Here, we report that a natural compound of the hydroxybenzoquinone class, embelin, specifically inhibits H3Lys9 acetylation in mice and inhibits recombinant PCAF-mediated acetylation with near complete specificity <i>in vitro</i>. Furthermore, using embelin, we have identified the gene networks that are regulated by PCAF during muscle differentiation, further highlighting the broader regulatory functions of PCAF in muscle differentiation in addition to the regulation via MyoD acetylation

Probing p300/CBP Associated Factor (PCAF)-Dependent Pathways with a Small Molecule Inhibitor

PCAF (KAT2B) belongs to the GNAT family of lysine acetyltransferases (KAT) and specifically acetylates the histone H3K9 residue and several nonhistone proteins. PCAF is also a transcriptional coactivator. Due to the lack of a PCAF KAT-specific small molecule inhibitor, the exclusive role of the acetyltransferase activity of PCAF is not well understood. Here, we report that a natural compound of the hydroxybenzoquinone class, embelin, specifically inhibits H3Lys9 acetylation in mice and inhibits recombinant PCAF-mediated acetylation with near complete specificity <i>in vitro</i>. Furthermore, using embelin, we have identified the gene networks that are regulated by PCAF during muscle differentiation, further highlighting the broader regulatory functions of PCAF in muscle differentiation in addition to the regulation via MyoD acetylation

Probing p300/CBP Associated Factor (PCAF)-Dependent Pathways with a Small Molecule Inhibitor

PCAF (KAT2B) belongs to the GNAT family of lysine acetyltransferases (KAT) and specifically acetylates the histone H3K9 residue and several nonhistone proteins. PCAF is also a transcriptional coactivator. Due to the lack of a PCAF KAT-specific small molecule inhibitor, the exclusive role of the acetyltransferase activity of PCAF is not well understood. Here, we report that a natural compound of the hydroxybenzoquinone class, embelin, specifically inhibits H3Lys9 acetylation in mice and inhibits recombinant PCAF-mediated acetylation with near complete specificity <i>in vitro</i>. Furthermore, using embelin, we have identified the gene networks that are regulated by PCAF during muscle differentiation, further highlighting the broader regulatory functions of PCAF in muscle differentiation in addition to the regulation via MyoD acetylation