Previous studies of native-state peptide hydrogen atom (NH) exchange in turkey ovomucoid third domain (OMTKY3) yielded the thermodynamics and kinetics of unfolding and folding for the 14 slowest-exchanging peptide hydrogen atoms (NHs). Unfolding rate constants and free energies for nine of the NHs are very similar, suggesting that these NHs exchange during a single cooperative unfolding event. Electrospray ionization mass spectrometry (ESI-MS) has been used to test this hypothesis. ESI-MS data and MS peak simulations suggest that this hypothesis is incorrect: in spite of the similarity in their unfolding rate constants, only three to five of the nine residues exchange in a cooperative manner. Thus, residues with similar thermodynamics and kinetics of exchange are probably involved in multiple conformational equilibria. Overall, combined NMR and MS analysis of NH exchange provides a rich and complex picture of the ensemble properties of native proteins.

Download full-text PDF

Source
http://dx.doi.org/10.1006/jmbi.1998.2338DOI Listing

Publication Analysis

Top Keywords

combined nmr
8
nmr analysis
8
peptide hydrogen
8
thermodynamics kinetics
8
unfolding rate
8
rate constants
8
exchange
6
defining protein
4
protein ensembles
4
ensembles native-state
4

Similar Publications

The brain undergoes atrophy and cognitive decline with advancing age. The utilization of brain age prediction represents a pioneering methodology in the examination of brain aging. This study aims to develop a deep learning model with high predictive accuracy and interpretability for brain age prediction tasks.

View Article and Find Full Text PDF

Proton magnetic resonance spectroscopy (MRS) offers a non-invasive, repeatable, and reproducible method for in vivo metabolite profiling of the brain and other tissues. However, metabolite fingerprinting by MRS requires high signal-to-noise ratios for accurate metabolite quantification, which has traditionally been limited to large volumes of interest, compromising spatial fidelity. In this study, we introduce a new optimized pipeline that combines LASER MRS acquisition at 11.

View Article and Find Full Text PDF

Heart failure is a complex clinical syndrome and pediatric heart failure (PHF) has a high mortality rate. Early diagnosis is crucial for treatment and management of PHF. In clinical practice, various tests and examinations play a key role in the diagnosis of PHF, including continuously updated biomarkers, echocardiography, and cardiac magnetic resonance imaging.

View Article and Find Full Text PDF

Arrhythmogenic calmodulin variants D131E and Q135P disrupt interaction with the L-type voltage-gated Ca channel (Ca1.2) and reduce Ca-dependent inactivation.

Acta Physiol (Oxf)

February 2025

Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, UK.

Aim: Long QT syndrome (LQTS) and catecholaminergic polymorphism ventricular tachycardia (CPVT) are inherited cardiac disorders often caused by mutations in ion channels. These arrhythmia syndromes have recently been associated with calmodulin (CaM) variants. Here, we investigate the impact of the arrhythmogenic variants D131E and Q135P on CaM's structure-function relationship.

View Article and Find Full Text PDF

A novel method was established using a restricted access material combined with a molecularly imprinted polymer (RAM-MIP) as the sorbent material in solid phase extraction (SPE) for clean-up of α-endosulfan, β-endosulfan, endosulfate, endosulfan-ether, endosulfan lactone, heptachlor, heptachlor--epoxide, and heptachlor--epoxide in pork and gas chromatography (GC) for determination. The RAM-MIP was prepared by precipitation polymerization by using endosulfan as the template, methacrylic acid (MAA) as the monomer, glycidyl methacrylate (GMA) as the pro-hydrophilic co-monomer, ethylene glycol dimethacrylate (EGDMA) as the crosslinker, azobisisobutyronitrile (AIBN) as the initiator, and toluene as the porogen. Ultraviolet spectroscopy (UV) and H-nuclear magnetic resonance (H-NMR) analysis verified that MAA interacted specifically with endosulfan in a ratio of 1 : 1 in the pre-polymerization solution.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!