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Title: “Fishing out elusive species from chemical reactions” Prof. Shibdas Banerjee will be giving a talk at CBC’s analytical/physical seminar series. Shibdas is currently an Assistant Professor at Indian Institute of Science Education and Research Tirupati. He recently completed his postdoctoral studies with Prof. Dick Zare at Stanford University. Date: August 30th, 2021 Time: 4:10 […]

Amino-acid side-chain properties in proteins are key determinants of protein function. NMR spin relaxation of side chains is an important source of information about local protein dynamics and flexibility. However, traditional solution NMR relaxation methods are most sensitive to sub-nanosecond dynamics lacking information on slower ns-μs time-scale motions. Nanoparticle-assisted NMR spin relaxation (NASR) of methyl-side chains is introduced here as a window into these ns-μs dynamics. NASR...

Amino-acid side-chain properties in proteins are key determinants of protein function. NMR spin relaxation of side chains is an important source of information about local protein dynamics and flexibility. However, traditional solution NMR relaxation methods are most sensitive to sub-nanosecond dynamics lacking information on slower ns-μs time-scale motions. Nanoparticle-assisted NMR spin relaxation (NASR) of methyl-side chains is introduced here as a window into these ns-μs dynamics. NASR...

The sensitivity-enhanced HSQC, as well as HSQC-TOCSY, experiments have been modified for incorporation into NOAH (NMR by Ordered Acquisition using ¹H detection) supersequences, adding diversity for ^(13)C and ^(15)N modules. Importantly, these heteronuclear modules have been specifically tailored to preserve the magnetisation required for subsequent acquisition of other heteronuclear or homonuclear modules in a supersequence. In addition, we present protocols for optimally combining HSQC and...

The sensitivity-enhanced HSQC, as well as HSQC-TOCSY, experiments have been modified for incorporation into NOAH (NMR by Ordered Acquisition using ¹H detection) supersequences, adding diversity for ^(13)C and ^(15)N modules. Importantly, these heteronuclear modules have been specifically tailored to preserve the magnetisation required for subsequent acquisition of other heteronuclear or homonuclear modules in a supersequence. In addition, we present protocols for optimally combining HSQC and...

Two limiting cases of molecular recognition, induced fit (IF) and conformational selection (CS), play a central role in allosteric regulation of natural systems. The IF paradigm states that a substrate "instructs" the host to change its shape after complexation, while CS asserts that a guest "selects" the optimal fit from an ensemble of preexisting host conformations. With no studies that quantitatively address the interplay of two limiting pathways in abiotic systems, we herein and for the...

Two limiting cases of molecular recognition, induced fit (IF) and conformational selection (CS), play a central role in allosteric regulation of natural systems. The IF paradigm states that a substrate "instructs" the host to change its shape after complexation, while CS asserts that a guest "selects" the optimal fit from an ensemble of preexisting host conformations. With no studies that quantitatively address the interplay of two limiting pathways in abiotic systems, we herein and for the...

Sensitivity-improved versions of two-dimensional (2D) ^(13)C-¹H HSQC (heteronuclear single quantum coherence) and HSQC-TOCSY (HSQC-total correlation spectroscopy) NMR experiments optimized for small biological molecules and their complex mixtures encountered in metabolomics are presented that preserve the magnetization of ¹H spins not directly attached to ^(13)C spins. This allows (i) the application of rapid acquisition techniques to substantially shorten measurement time and (ii) their...

Sensitivity-improved versions of two-dimensional (2D) ^(13)C-¹H HSQC (heteronuclear single quantum coherence) and HSQC-TOCSY (HSQC-total correlation spectroscopy) NMR experiments optimized for small biological molecules and their complex mixtures encountered in metabolomics are presented that preserve the magnetization of ¹H spins not directly attached to ^(13)C spins. This allows (i) the application of rapid acquisition techniques to substantially shorten measurement time and (ii) their...

Prof. Justin Benesch, University of Oxford “Combining native mass spectrometry with mass photometry to elucidate the assembly of ultra-heterogeneous protein assemblies” Date: March 23rd, 2021 Time: 5:30 PM EST Zoom: link provided via email or contact badu-tawiah.1@osu.edu

Dr. Candice Ulmer, Research Chemist, CDC “The Development of Routine and Reference Measurement Procedures to Support the Accurate Reporting of Clinical Measurements” Date: February 23rd, 2021 Time: 5:30 PM EST Zoom: link provided via email or contact badu-tawiah.1@osu.edu

Dr. Michael Wleklinski, Senior Scientist, Merck & Co. “High Throughput Synthesis and Screening: My Journey from Academia to Industry” Date: December 8, 2021 Time: 5:30 PM EST Zoom: link provided via email or contact badu-tawiah.1@osu.edu

Prof. Julia Laskin, Purdue University “Ambient imaging of biological samples using nanospray desorption electrospray ionization (nano-DESI) mass spectrometry” Date: December 8, 2020 Time: 5:30 PM EST Zoom: link provided via email or contact badu-tawiah.1@osu.edu

Biological molecules interact with silica (SiO(2)) surfaces with binding affinities that greatly vary depending on their physical-chemical properties. However, the quantitative characterization of biological compounds adsorbed on silica surfaces, especially of compounds involved in fast, reversible interactions, has been challenging, and the driving forces are not well understood. Here, we show how carbon-13 NMR spin relaxation provides quantitative atomic-detail information about the transient...

Biological molecules interact with silica (SiO(2)) surfaces with binding affinities that greatly vary depending on their physical-chemical properties. However, the quantitative characterization of biological compounds adsorbed on silica surfaces, especially of compounds involved in fast, reversible interactions, has been challenging, and the driving forces are not well understood. Here, we show how carbon-13 NMR spin relaxation provides quantitative atomic-detail information about the transient...

Proanthocyanidins (condensed tannins) are important in food chemistry, agriculture, and health, driving demand for improvements in structure determination. We used ultrahigh resolution Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS) methods to determine the exact composition of individual species in heterogeneous mixtures of proanthocyanidin polymers from Sorghum bicolor grain and Neptunia lutea leaves. Fragmentation patterns obtained with FT-ICR ESI MS-MS (electrospray...

Proanthocyanidins (condensed tannins) are important in food chemistry, agriculture, and health, driving demand for improvements in structure determination. We used ultrahigh resolution Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS) methods to determine the exact composition of individual species in heterogeneous mixtures of proanthocyanidin polymers from Sorghum bicolor grain and Neptunia lutea leaves. Fragmentation patterns obtained with FT-ICR ESI MS-MS (electrospray...

1. Dr. Maya Reimi Sipala, Scientist at Balazs NanoAnalysis, “HR-ICP-MS Applications in the Semiconductor Industry” Date: November 17, 2020 Time: 5:30 PM EST Zoom: to be provided via email

Prof. Peter Nemes, University of Maryland, “Single-cell Mass Spectrometry Discovers Metabolic Effectors of Cell Differentiation” Date: November 2, 2020 Time: 4:10 PM EST Place: Zoom – link provided via email or contact badu-tawiah.1@osu.edu

Cyclic peptides are capable of binding to challenging targets (e.g., proteins involved in protein-protein interactions) with high affinity and specificity, but generally cannot gain access to intracellular targets because of poor membrane permeability. In this work, we discovered a conformationally constrained cyclic cell-penetrating peptide (CPP) containing a d-Pro-l-Pro motif, cyclo(AFΦrpPRRFQ) (where Φ is l-naphthylalanine, r is d-arginine, and p is d-proline). The structural constraints...