Publications by authors named "Stephen Nakazawa-Hewitt"
Griselimycin, a cyclic depsidecapeptide produced by Streptomyces griseus, is a promising lead inhibitor of the sliding clamp component of bacterial DNA polymerases (β-subunit of Escherichia coli DNA pol III). It was previously shown to inhibit the Mycobacterium tuberculosis β-clamp with remarkably high affinity and selectivity - the peptide lacks any interaction with the human sliding clamp. Here, we used a structural genomics approach to address the prospect of broader-spectrum inhibition, in particular of β-clamps from Gram-negative bacterial targets.
View Article and Find Full Text PDFLysyl-tRNA synthetase as a drug target in malaria and cryptosporidiosis.
Proc Natl Acad Sci U S A
April 2019
Article Synopsis
- Malaria and cryptosporidiosis, both caused by apicomplexan parasites, are significant contributors to child mortality, highlighting the urgent need for new drugs.
- The natural product cladosporin shows effectiveness against different stages of these diseases and targets lysyl-tRNA synthetase (KRS1).
- Researchers have identified and optimized a series of selective KRS inhibitors, demonstrating their potential in mouse models for both malaria and cryptosporidiosis, marking KRSs as promising drug development targets.
Article Synopsis
- Researchers identified prolyl-tRNA synthetase (ProRS) in the malaria-causing parasite Plasmodium falciparum (Pf) as a promising drug target, but selective inhibitors for this target were previously unreported.
- By screening around 40,000 compounds, the study discovered two new allosteric inhibitors that specifically target PfProRS with over 100 times more selectivity than the human version (HsProRS).
- The findings, supported by X-ray crystallography, pave the way for further medicinal chemistry efforts to optimize these inhibitors for potential malaria treatments without the toxicity associated with existing drugs.
Article Synopsis
- - The lack of collaboration between academia and the pharmaceutical industry limits new drug discovery, but open source drug initiatives, like sharing physical compounds, could help bridge this gap and accelerate research.
- - The Medicines for Malaria Venture created the Malaria Box, a collection of over 400 compounds tested against malaria, which has been shared with almost 200 research groups, encouraging public data sharing on screening results.
- - Recent findings from the Malaria Box screenings revealed mechanisms of action for many compounds against various life stages of the malaria parasite, and some showed effectiveness against other pathogens and cancer cell lines, providing valuable data for further drug development.
Structures of prostaglandin F synthase from the protozoa Leishmania major and Trypanosoma cruzi with NADP.
Acta Crystallogr F Struct Biol Commun
May 2015
Article Synopsis
- The crystal structures of prostaglandin F synthase (PGF) from two protozoa, Leishmania major and Trypanosoma cruzi, have been resolved with and without the cofactor NADP at varying resolutions (2.6 Å to 1.25 Å).
- These structures were analyzed using molecular replacement techniques and achieved R factors indicating good quality of the data (less than 18.6% for R and less than 22.9% for Rfree).
- PGF is identified as a potential therapeutic target in treating infections caused by these protozoa.
Structures of a histidine triad family protein from Entamoeba histolytica bound to sulfate, AMP and GMP.
Acta Crystallogr F Struct Biol Commun
May 2015
Article Synopsis
- Three high-resolution structures of the histidine triad protein from Entamoeba histolytica were determined at the Seattle Structural Genomics Center for Infectious Disease, which is linked to amoebic dysentery.
- * The structures show different molecules bound in the active site: sulfate, AMP, and GMP, with sulfate positioned similarly to the α-phosphate of the nucleotides.
- * The carbon alpha (C(α)) backbones of all three structures are nearly identical, with very small differences in their alignment (r.m.s.d.s between 0.06 and 0.13 Å).
Immobilized metal-affinity chromatography protein-recovery screening is predictive of crystallographic structure success.
Acta Crystallogr Sect F Struct Biol Cryst Commun
September 2011
The recombinant expression of soluble proteins in Escherichia coli continues to be a major bottleneck in structural genomics. The establishment of reliable protocols for the performance of small-scale expression and solubility testing is an essential component of structural genomic pipelines. The SSGCID Protein Production Group at the University of Washington (UW-PPG) has developed a high-throughput screening (HTS) protocol for the measurement of protein recovery from immobilized metal-affinity chromatography (IMAC) which predicts successful purification of hexahistidine-tagged proteins.
View Article and Find Full Text PDFArticle Synopsis
- Structural genomics projects need X-ray diffraction and NMR spectroscopy for solving protein structures, and advanced facilities are often required for data collection.
- The paper introduces a new laboratory-scale synchrotron light source called the Compact Light Source, which can replicate many key synchrotron applications in X-ray science.
- Successful tests showcased its capability by determining the high-resolution structure of a protein from Mycobacterium tuberculosis using X-ray diffraction data from this new source.
Article Synopsis
- Protein crystallography is a powerful method for uncovering biological structures, but creating suitable crystals can be very challenging.
- A new hybrid predictive model combines both experimental data and information derived from protein sequences, utilizing unique variables like R(30), which represent protein characteristics at different temperatures.
- This hybrid model outperforms traditional sequence-based methods, making it a valuable tool for guiding structural genomics and enhancing the work of structural biology labs.