[NMR paper] 129Xe NMR-Protein Sensor Reveals Cellular Ribose Concentration.

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129Xe NMR-Protein Sensor Reveals Cellular Ribose Concentration.

Related Articles 129Xe NMR-Protein Sensor Reveals Cellular Ribose Concentration.

Anal Chem. 2020 Sep 08;:

Authors: Zemerov SD, Roose BW, Farenhem KL, Zhao Z, Stringer MA, Goldman A, Speicher DW, Dmochowski IJ

Abstract
Dysregulation of cellular ribose uptake can be indicative of metabolic abnormalities or tumorigenesis. However, analytical methods are currently limited for quantifying ribose concentration in complex biological samples. Here, we utilize the highly-specific recognition of ribose by ribose binding protein (RBP) to develop a single-protein ribose sensor detectable via a sensitive NMR technique known as hyperpolarized (hp) 129Xe chemical exchange saturation transfer (hyper-CEST). We demonstrate that RBP, with a tunable ribose binding site and further engineered to bind xenon, enables the quantitation of ribose over a wide concentration range (nM-mM). Ribose binding induces the RBP 'closed' conformation, which slows Xe exchange to a rate detectable by hyper-CEST. Such detection is remarkably specific for ribose, with minimal background signal from endogenous sugars of similar size and structure, e.g., glucose or ribose-6-phosphate. Ribose concentration was measured for mammalian cell lysate and serum, which led to estimates of low-mM ribose in a HeLa cell line. This highlights the potential for using genetically encoded periplasmic binding proteins such as RBP to measure metabolites in different biological fluids, tissues, and physiologic states.


PMID: 32897053 [PubMed - as supplied by publisher]



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