Biology subjects

Frenkel, M. S.

Publications and source records attributed to Frenkel, M. S..

3 recordsLinked to original sources

bioRxiv2020

Chiral evasion and stereospecific antifolate resistance in Staphylococcus aureus

Antimicrobial resistance is a health care crisis. The resistance-conferring mutation F98Y in Staphylococcus aureus dihydrofolate reductase (SaDHFR) reduces effectiveness of antifolates, e.g., trimethoprim (TMP). Although propargyl-linked antifolates (PLAs) are much more resilient than TMP towards F98Y, this substitution still vitiates their inhibition potency. Surprisingly, differences in the enantiomeric configuration at the stereogenic center of PLAs influence the isomeric state of NADPH cofactor. Is resistance correlated with chiral evasion? A mechanism of action underpinning this coupling is unknown. To understand the molecular basis of F98Y-mediated resistance and how PLAs inhibition drives NADPH isomeric states, we used OSPREY to analyze a comprehensive suite of structural, biophysical, biochemical, and computational data. We present a model showing how F98Y SaDHFR exploits a different anomeric configuration of NADPH to evade certain PLAs inhibition, while other PLAs remain resilient to resistance. Our model should enable general design of inhibitors that are resilient to chiral evasion.

biochemistry↗

bioRxiv2019

Toward Broad Spectrum DHFR inhibitors Targeting Trimethoprim Resistant Enzymes Identified in Clinical Isolates of Methicillin-Resistant Staphylococcus aureus

The spread of plasmid borne resistance enzymes in clinical Staphylococcus aureus isolates is rendering trimethoprim and iclaprim, both inhibitors of dihydrofolate reductase (DHFR), ineffective. Continued exploitation of these targets will require compounds that can broadly inhibit these resistance-confering isoforms. Using a structure-based approach, we have developed a novel class of ionized non-classical antifolates (INCAs) that capture the molecular interactions that have been exclusive to classical antifolates. These modifications allow for a greatly expanded spectrum of activity across these pathogenic DHFR isoforms, while maintaining the ability to penetrate the bacterial cell wall. Using biochemical, structural and computational methods, we are able to optimize these inhibitors to the conserved active sites of the endogenous and trimethoprim resistant DHFR enzymes. Here, we report a series of INCA compounds that exhibit low nanomolar enzymatic activity and potent cellular activity with human selectivity against a panel of clinically relevant TMPR MRSA isolates.

biochemistry↗

bioRxiv2018

OSPREY 3.0: Open-Source Protein Redesign for You, with Powerful New Features

We present O_SCPCAPOSPREYC_SCPCAP 3.0, a new and greatly improved release of the O_SCPLOWOSPREYC_SCPLOW protein design software. O_SCPLOWOSPREYC_SCPLOW 3.0 features a convenient new Python interface, which greatly improves its ease of use. It is over two orders of magnitude faster than previous versions of O_SCPLOWOSPREYC_SCPLOW when running the same algorithms on the same hardware. Moreover, O_SCPLOWOSPREYC_SCPLOW 3.0 includes several new algorithms, which introduce substantial speedups as well as improved biophysical modeling. It also includes GPU support, which provides an additional speedup of over an order of magnitude. Like previous versions of O_SCPLOWOSPREYC_SCPLOWO_SCPCAP, C_SCPCAPO_SCPLOWOSPREYC_SCPLOW 3.0 offers a unique package of advantages over other design software, including provable design algorithms that account for continuous flexibility during design and model conformational entropy. Finally, we show here empirically that O_SCPLOWOSPREYC_SCPLOW 3.0 accurately predicts the effect of mutations on protein-protein binding. O_SCPLOWOSPREYC_SCPLOW 3.0 is available at http://www.cs.duke.edu/donaldlab/osprey.php as free and open-source software.\n\nO_TEXTBOX\n\nWe present the third major release of the OSPREY protein design software, along with comparisons to experimental data that confirm its ability to optimize protein mutants for desired functions. osprey 3.0 has significant efficiency, ease-of-use, and algorithmic improvements over previous versions, including GPU acceleration and a new Python interface.\n\nC_TEXTBOX\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=162 SRC=\"FIGDIR/small/306324v1_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (54K):\norg.highwire.dtl.DTLVardef@f08b0dorg.highwire.dtl.DTLVardef@393b61org.highwire.dtl.DTLVardef@16997ddorg.highwire.dtl.DTLVardef@1713405_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioinformatics↗