@article {46391, title = {Structural studies on an atypical Rho GTPase RhoH}, journal = {Acta Crystallographica A-Foundation and Advances}, volume = {70}, year = {2014}, month = {MAY}, pages = {C389}, type = {Meeting Abstract}, keywords = {lymphoma, RhoH, TCR signalling}, issn = {2053-2733}, author = {Motiwala, Zenia and Kulkarni, Kiran} } @article {46888, title = {Overturning the peribysin family natural products isolated from periconia byssoides OUPS-N133: synthesis and stereochemical revision of peribysins A, B, C, F, and G}, journal = {Organic Letters}, volume = {22}, year = {2020}, month = {APR}, pages = {3104-3109}, type = {Article}, abstract = {

Herein we report the stereochemical revision of peribysins A, B, C, F, and G, guided by enantiospecific total synthesis starting from (+)-nootkatone. Furthermore, we reconfirmed the absolute stereochemistry of peribysin Q The highlights of the synthesis are enone transposition and kinetic iodination resulting in separation of diastereomers. Our findings coupled with synthetic and biological data previously reported by Danishefsky{\textquoteright}s group suggest that the original stereochemistries of peribysins A, B, C, F, and G were misassigned.

}, issn = {1523-7060}, doi = {10.1021/acs.orglett.0c00857}, author = {Athawale, Paresh R. and Kalmode, Hanuman P. and Motiwala, Zenia and Kulkarni, Kiran A. and Reddy, D. Srinivasa} } @article {47111, title = {Expression, purification and crystallization of Asrij, A novel scaffold transmembrane protein}, journal = {Journal of Membrane Biology}, volume = {254}, year = {2021}, month = {FEB}, pages = {65-74}, type = {Article}, abstract = {

Asrij/OCIAD1 is a scaffold transmembrane protein belonging to the Ovarian Carcinoma Immunoreactive Antigen Domain containing protein family. In Drosophila and mouse models, Asrij localizes at the endosomal and mitochondrial membrane and is shown to regulate the stemness of hematopoietic stem cells. Interaction of Asrij with ADP Ribosylation Factor 1 (Arf1) is shown to be crucial for hematopoietic niche function and prohemocyte maintenance. Here, we report the heterologous expression, standardization of detergents and purification methodologies for crystallization of Asrij/OCIAD1. To probe the activity of bacterially expressed Asrij, we developed a protein complementation assay and conclusively show that Asrij and Arf1 physically interact. Further, we find that sophorolipids improve the solubility and monodispersibility of Asrij. Hence, we propose that sophorolipids could be novel additives for stabilization of membrane proteins. To our knowledge, this is the first study detailing methodology for the production and crystallization of a heterologously expressed scaffold membrane protein and will be widely applicable to understand membrane protein structure and function. Graphic

}, keywords = {Asrij/OCIAD1, Membrane protein crystallography, sophorolipids}, issn = {0022-2631}, doi = {10.1007/s00232-020-00166-7, Early Access Date = JAN 2021}, author = {Motiwala, Zenia and Darne, Priti and Prabhune, Asmita and Inamdar, Maneesha S. and Kulkarni, Kiran} } @article {48068, title = {Postmodification of voxelotor (GBT 440) via [Rh]-catalyzed cross dehydrogenative coupling with olefins br}, journal = {Bioorganic \& Medicinal Chemistry Letters}, volume = {77}, year = {2022}, month = {DEC}, pages = {129022}, type = {Article}, abstract = {

The directed Rh(III)-catalyzed cross dehydrogenative coupling of the pyrazole unit of the GBT-440 scaffold has been explored with simple as well as conjugated olefins to synthesize post-functionalized GBT-440 analogues. The screening of these synthesized compounds for improving the oxygen binding efficiency of the hemoglobin isolated from the sickled red blood cells revealed that some of these compounds are as good as GBT-440.

}, keywords = {CDC Coupling, GBT-440 (Voxelotor), Rh(III) catalysis, sickle cell anemia}, issn = {0960-894X}, doi = {10.1016/j.bmcl.2022.129022}, author = {Kalshetti, Rupali G. and Rajput, Raveena and Motiwala, Zenia and Reddy, D. Srinivasa and Kulkarni, Kiran A. and V. Ramana, Chepuri} } @article {48826, title = {Synthesis, biological evaluation and docking studies of silicon incorporated diarylpyrroles as MmpL3 inhibitors: an effective strategy towards development of potent anti-tubercular agents}, journal = {European Journal of Medicinal Chemistry}, volume = {259}, year = {2023}, month = {NOV }, pages = {115633}, type = {Article}, abstract = {

Growing global demand for new molecules to treat tuberculosis has created an urgent need to develop novel strategies to combat the menace. BM212 related compounds were found to be potent anti-TB agents and they inhibit mycolic acid transporter, MmpL3, a known potent drug target from Mycobacterium tuberculosis. In order to enhance their inhibitory potency, several silicon analogues of diarylpyrroles related to BM212 were designed, synthesized, and evaluated for anti-tubercular activities. In Alamar blue assay, most of the silicon-incorporated compounds were found to be more potent than the parent compound (BM212), against Mycobacterium tuberculosis (MIC = 1.7 \& mu;M, H37Rv). Docking results from the crystal structure of MmpL3 and silicon analogues as pharmacophore model also strongly correlate with the biological assays and suggest that the incorporation of silicon in the inhibitor scaffold could enhance their potency by stabilizing the hydrophobic residues at the binding pocket. The best docking hit, compound 12 showed an MIC of 0.1 \& mu;M against H37Rv with an acceptable in vitro ADME profile and excellent selectivity index. Overall, the present study indicates that, the designed silicon analogues, especially compound 12 could be a good inhibitor for an intrinsically flexible drug-binding pocket of MmpL3 and has potential for further development as anti-tubercular agents.

}, keywords = {antibiotic, BM212, docking studies, MmpL3 inhibitor, Silicon analogue, tuberculosis}, issn = {0223-5234}, doi = {10.1016/j.ejmech.2023.115633}, author = {Vasudevan, N. and Motiwala, Zenia and Ramesh, Remya and Wagh, Sachin B. and Shingare, Rahul D. and Katte, Revansiddha and Anand, Amitesh and Choudhary, Sushil and Kumar, Ajay and Gokhale, Rajesh S. and Kulkarni, Kiran A. and Reddy, D. Srinivasa} } @article {48673, title = {Wavelet coherence phase analysis decodes the universal switching mechanism of Ras GTPase superfamily}, journal = {iScience}, volume = {26}, year = {2023}, month = {JUL}, pages = {107031}, type = {Article}, abstract = {

The Ras superfamily of GTPases regulate critical cellular processes by shuttling between GTP-bound ON and GDP-bound OFF states. This switching mechanism is attributed to the conformational changes in two loops, SWI and SWII, upon GTP binding and hydrolysis. Since these conformational changes vary across the Ras superfamily, there is no generic parameter to define their functional states. A unique wavelet coherence (WC) analysis-based approach developed here shows that the structural changes in switch regions could be mapped onto the wavelet coherence phase couplings (WPCs). Thus, WPCs could serve as unique parameters to define their functional states. Disentanglement of WPCs in oncogenic GTPases shows how breakdown of structural allostery leads to their aberrant function. These observations stand out even for simulated ensemble of switch region conformers. Overall, for the first time, we show that WPCs could unravel the latent structural deviations in Ras proteins to decode their universal switching mechanism.

}, doi = {10.1016/j.isci.2023.107031}, author = {Motiwala, Zenia and Sandholu, Anand S. and Sengupta, Durba and Kulkarni, Kiran} }