A5058786131- Enzyme Structure and Function
- Protein Structure and Dynamics
- X-ray Diffraction in Crystallography
- Biochemical and Molecular Research
- Advanced X-ray Imaging Techniques
- Crystallization and Solubility Studies
- Calcium signaling and nucleotide metabolism
- PARP inhibition in cancer therapy
- Inorganic Chemistry and Materials
- Folate and B Vitamins Research
- Mass Spectrometry Techniques and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Toxin Mechanisms and Immunotoxins
- Cancer, Hypoxia, and Metabolism
- Amino Acid Enzymes and Metabolism
- Erythrocyte Function and Pathophysiology
- Enzyme function and inhibition
- Semiconductor materials and interfaces
- Hemoglobin structure and function
- Advancements in Battery Materials
- Research Data Management Practices
- Extraction and Separation Processes
- Quasicrystal Structures and Properties
- Animal Genetics and Reproduction
- Aluminum Alloys Composites Properties
Cornell University
2010-2022
Cornell High Energy Synchrotron Source
2007-2014
Virginia Commonwealth University
2004
The structure of bovine intestinal calcium-binding protein (ICaBP) has been determined crystallographically at a resolution 2.3 A and refined by least
In conventional x-ray diffraction experiments on single crystals, essentially monochromatic x-rays are used. If polychromatic derived from a synchrotron radiation spectrum used, they generate Laue pattern. patterns crystals of macromolecules can be obtained in less-than 1 second, and significant damage does not occur over the course an exposure. Integrated intensities without rotation crystal, individual structure factors may extracted for most reflections. The technique thus offers...
An emulsion-based serial crystallographic technology has been developed, in which nanolitre-sized droplets of protein solution are encapsulated oil and stabilized by surfactant. Once the first crystal a drop is nucleated, small volume generates negative feedback mechanism that lowers supersaturation. This exploited to produce one per drop. Diffraction data measured, at time, from series room-temperature crystals stored on an X-ray semi-transparent microfluidic chip, 93% complete set obtained...
Perturbations in folate-mediated one-carbon metabolism increase rates of uracil misincorporation into DNA during replication, impair cellular methylation reactions, and risk for neural tube defects cancer. One-carbon is compromised by folate deficiency common genetic polymorphisms. In this study, the mechanism preferential partitioning cytoplasmic serine hydroxymethyltransferase (cSHMT)-derived methylenetetrahydrofolate to de novo thymidylate biosynthesis was investigated. The cSHMT enzyme...
Two new cyclic heptapeptides, serinocyclins A (1) and B (2), were isolated from conidia of the entomopathogenic fungus Metarhizium anisopliae. Structures elucidated by a combination mass spectrometric, NMR, X-ray diffraction techniques. Serinocyclin contains three serine units, hydroxyproline (Hyp), β-alanine (β-Ala), two uncommon nonproteinogenic amino acids, 1-aminocyclopropane-1-carboxylic acid (Acc) γ-hydroxylysine (HyLys). The peptide sequence established for 1 NMR is...
Cancer cells frequently exhibit uncoupling of the glycolytic pathway from TCA cycle (i.e., "Warburg effect") and as a result, often become dependent on their ability to increase glutamine catabolism. The mitochondrial enzyme Glutaminase C (GAC) helps satisfy this 'glutamine addiction' cancer by catalyzing hydrolysis glutamate, which is then converted TCA-cycle intermediate α-ketoglutarate. This makes GAC an intriguing drug target spurred molecules derived...
Serine hydroxymethyltransferase (SHMT) is a pyridoxal phosphate-dependent enzyme that catalyzes the reversible conversion of serine and tetrahydrofolate to glycine methylenetetrahydrofolate. This reaction generates single carbon units for purine, thymidine, methionine biosynthesis. The homotetramer comprising two obligate dimers four phosphate-bound active sites. mammalian present in cells both catalytically inactive forms. form ternary complex results from binding 5-formyltetrahydrofolate...
Serine hydroxymethyltransferase (SHMT) catalyzes the reversible interconversion of serine and glycine with tetrahydrofolate serving as one-carbon carrier. SHMT also folate-independent retroaldol cleavage allothreonine 3-phenylserine irreversible conversion 5,10-methenyltetrahydrofolate to 5-formyltetrahydrofolate. Studies wild-type site mutants have failed clearly establish mechanism this enzyme. The 3-hydroxy amino acids an aldehyde occurs by a mechanism. However, folate-dependent can be...
A fixed-target approach to high-throughput room-temperature serial synchrotron crystallography with oscillation is described. Patterned silicon chips microwells provide high crystal-loading density an extremely hit rate. The microfocus, undulator-fed beamline at CHESS, which has compound refractive optics and a fast-framing detector, was built optimized for this experiment. method described here collects 1–5° of data per crystal room temperature fast (10° s −1 ) rates translation times,...
5-Formyltetrahydrofolate (5-formylTHF) is the only folate derivative that does not serve as a cofactor in folate-dependent one-carbon metabolism. Two metabolic roles have been ascribed to this derivative. It has proposed 1) storage form of because it chemically stable and accumulates seeds spores 2) regulate metabolism by inhibiting enzymes, specifically targeting de novo purine biosynthesis. Methenyltetrahydrofolate synthetase (MTHFS) enzyme metabolizes 5-formylTHF catalyzes its...
Carbonic anhydrases (CAs) are enzymes that catalyze the hydration/dehydration of CO2/HCO3– with rates approaching diffusion-controlled limits (kcat/KM ∼ 108 M–1 s–1). This family has evolved disparate protein folds all perform same reaction at near catalytic perfection. Presented here is a structural study β-CA (psCA3) expressed in Pseudomonas aeruginosa, complex CO2, using pressurized cryo-cooled crystallography. The structure been refined to 1.6 Å resolution Rcryst and Rfree values 17.3...
In addition to inhibiting insulin receptor and IGF1R kinase activity by directly binding the receptors, GRB10 can also negatively regulate IGF1 signaling mediating degradation through ubiquitination. It has been shown that interact with C2 domain of E3 ubiquitin ligase NEDD4 its Src homology 2 (SH2) domain. Therefore, might act as a connector, bringing close facilitate ubiquitination NEDD4. This is first case in which it found an SH2 could colocalize substrate. Here we report crystal...
High-pressure cryocooling (HPC) has been developed as a technique for reducing the damage that frequently occurs when macromolecular crystals are cryocooled at ambient pressure. Crystals typically pressurized around 200 MPa and then cooled to liquid nitrogen temperature under pressure; this process reduces need penetrating cryoprotectants, well due cryocooling, but does not improve diffraction quality of as-grown crystals. Here it is reported HPC using pressure above 300 can reduce lattice...
X-ray Laue diffraction patterns with an exposure time of 120 ps have been obtained from single crystals indole alkaloid and the enzyme lysozyme using X-rays emitted as a bunch electrons traverses hard undulator inserted in CESR, Cornell Electron–Positron Storage Ring. The were recorded on sensitive storage-phosphor detector. Despite complexities posed by sharp variation incident spectrum wavelength weakness patterns, accurate crystallographic structure amplitudes extracted intensities...
Crystal size is an important factor in determining the number of diffraction patterns which may be obtained from a protein crystal before severe radiation damage sets in. As dimensions decrease this reduced, eventually falling to one, at point complete data set must assembled using multiple crystals. When only single exposure collected each crystal, polychromatic Laue technique preferable monochromatic methods owing its simultaneous recording large fully recorded reflections per image. To...
A set of linked software modules has been installed at the A1 station CHESS, Cornell High Energy Synchrotron Source, which, with underlying hardware, allows crystallographic users facility to evaluate crystals, collect diffraction images and process rapidly assurance quality resultant data, thereby making most efficient use their beam time. The system includes a CCD detector its controlling software, graphical user interface, convenient oscillation camera featuring automated alignment X-ray...
The Macromolecular Diffraction Facility at the Cornell High Energy Synchrotron Source (MacCHESS) is a national research resource supported by National Center for Research Resources of US Institutes Health. MacCHESS pursuing several initiatives designed to benefit both CHESS users and wider structural biology community. Three are presented in further detail: microcrystallography, which aims improve collection diffraction data from crystals few micrometers across, or small well diffracting...
Fluorescence microscopy methods have seen an increase in popularity recent years for detecting protein crystals screening trays. The fluorescence-based crystal detection thus far relied on intrinsic UV-inducible tryptophan fluorescence, nonlinear optics or fluorescence the visible light range dependent soaked with fluorescent dyes. In this paper data are presented a novel visible-light-inducible autofluorescence arising from as result of general stabilization conjugated double-bond systems...
Mammalian serine hydroxymethyltransferase (SHMT) is a tetrameric, pyridoxal phosphate-dependent enzyme that catalyzes the reversible interconversion of and tetrahydrofolate to glycine methylenetetrahydrofolate. This reaction generates single-carbon units for purine, thymidine, methionine biosynthesis. Cytoplasmic SHMT (cSHMT) has been postulated channel one-carbon substituted folates various folate-dependent enzymes, alternative splicing cSHMT transcript may be mechanism enables specific...