A NMR method to determine the anomeric specificity of glucose phosphorylation

Richter, Thomas; Berger, Stefan

doi:10.1016/j.bmc.2013.03.008

Cited by 3 publications

(3 citation statements)

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“…This process can also be reversed by glucose-6-phosphatase (G6Pase) (Figure ). It was found that the hydroxyl group (−OH)-determined stereochemical structure has a great effect on these enzymatic processes. , For example, GK, HK, and G6Pase all show obvious anomeric specificity, where the phosphorylation rate generally takes preference to the β anomer (equatorial hydroxyl group at C1) over α one (axial hydroxyl group at C1). − In the next transformation from G6P to G1P, the transfer of the phosphate group from C6 to C1 is catalyzed by phosphoglucomutase (PGM), and αG1P is formed specifically by α-PGM (αPGM) (Figure ). In this process, only the gg rotamer of G6P (the dihedral angle O5–C5–C6–O6 is about −60°) is identified by αPGM during the reaction. , When αG1P is converted back to G6P, the stereochemistry of the C2–OH group becomes an important factor in substrate recognition, , for which the equatorial hydroxyl group at C2 shows specific contacts with αPGM but the axial one does not.…”

Section: Introductionmentioning

confidence: 99%

“…One of the popular spectral methods to investigate the stereochemical structure of glucose and its phosphates is NMR. Different anomers show characteristic chemical shifts, and different rotamers generate discrepant J H,H values. ,− Szeja et al demonstrated that density functional theory (DFT) combined with Raman and IR spectra could also provide a structural elucidation of βG6P . Nevertheless, these methods were still an indirect way to view the molecular chirality.…”

Section: Introductionmentioning

confidence: 99%

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Stereostructural Elucidation of Glucose Phosphorylation by Raman Optical Activity

et al. 2019

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Phosphorylation of glucose is the prime step in sugar metabolism and energy storage. Two key glucose phosphates are involved, that is, glucose 6-phosphate (G6P) and α-glucose 1-phosphate (αG1P). The chiral conformation of glucose, G6P, and αG1P plays an essential role in enzyme-mediated conversions. However, few techniques were able to give a direct view of the conformational changes from glucose to G6P and αG1P. Here, Raman optical activity (ROA) was used to elucidate the stereochemical evolution of glucose upon phosphorylation. ROA was found to be extremely sensitive to different phosphorylation sites. A characteristic ROA marker of (+)980 cm–1, originated from the phosphate group symmetric stretching vibration, is observed for αG1P with phosphorylation at chiral C1, while no corresponding ROA signal for G6P with phosphorylation at achiral C6 is observed. Phosphorylation-induced gauch–gauch (gg)/gauch–trans (gt) rotamer distribution changes can be sensitively probed by the sign of the ROA band around 1460 cm–1. A positive ROA band at 1465 cm–1 of glucose corresponds to a higher gt ratio, while a negative band at 1455 cm–1 of G6P suggests a dominant gg population, and the disappearance of this ROA band for αG1P indicates a nearly balanced gg/gt distribution. Meanwhile, the phosphorylation at C6 and C1 could cause dramatic reduction of the conformational flexibility of the adjacent C4–OH and C2–OH, respectively. These stereochemical changes revealed by ROA spectra offer a structural basis on the understanding of sugar phosphorylation from the perspective of chirality.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Stereostructural Elucidation of Glucose Phosphorylation by Raman Optical Activity

et al. 2019

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“…The characteristic chemical shifts of eight amino acids and sugars were observed around the region 4.10–1.98 ppm, which correspond to the -C H 2 - protons of amino acids, and 1.48–0.96 ppm, which correspond to the -C H - and -C H 3 protons of amino acids (Azizan et al 2018 ; Ma et al 2019 ; Iglesias et al 2019 ). The peaks around 5.20–3.82 ppm correspond to the -C H - protons of glucose and sucrose, and the peaks around 3.82–3.67 ppm correspond to the -C H 2 - protons of glucose and sucrose (Richter and Berger 2013 ). The representative proton signals of fucoxanthin (olefinic- H ), astaxanthin, lutein and zeaxanthin were observed at a chemical shift around 7.01–6.10 ppm (Zailanie and Purnomo 2017 ; Shumilina et al 2020 ; Otaka et al 2016 ; Iwai et al 2008 ).…”

Section: Resultsmentioning

confidence: 99%

Morphological and molecular comparison as a useful tool for identification of the three centric marine diatoms (Bacillariophyceae: Chaetoceros)

Kutako¹,

Hiransuchalert

Watchasit

et al. 2023

Arch Microbiol

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The objective of this study was to identify morphological and molecular comparison of three marine Chaetoceros species using microscopic observations, sequence analysis of 18S rDNA, random amplified polymorphic DNA (RAPD-PCR) barcoding and nuclear magnetic resonance (NMR) spectroscopy. Chaetoceros were obtained from three different algae laboratories: Center of Excellence for Marine Biotechnology (CEMB), Chanthaburi Coastal Fisheries Research and Development (CHAN) and Institute of Marine Science, Burapha University (BIM). Genomic DNA for the RAPD-PCR analysis was extracted using the phenol–chloroform method, followed by 18S rDNA amplification. The blast results of 18S rDNA sequence confirmed the significantly matched to C. gracilis for Chaetoceros BIM and CHAN and C. muelleri for Chaetoceros CEMB(e-value = 0.0, identity = 99%). The RAPD-PCR results revealed differences in the three Chaetoceros isolates with polymorphisms between 30.43% and 60.00%, and Chaetoceros CEMB showed high polymorphic bands. Scanning electron microscopy revealed that Chaetoceros CEMB were larger and had larger setae compared to the other isolates ( P < 0.05). The results of the NMR characterization of metabolites were consistent with the results of the sequence and morphological analyses. The concentrations of several metabolites, including chlorophyll c 1 , chlorophyll a, Myo-inositol, fucoxanthin, astaxanthin, lutein and zeaxanthin, were lower in Chaetoceros CEMB than in Chaetoceros BIM and CHAN. However, high concentrations of fatty acids, such as oleic acid, linoleic acid, α-linolenic acid and arachidic acid, were observed in all isolates. Generally, the results of this study will aid future studies examining the diversity of Chaetoceros in various cultural environments. Supplementary Information The online version contains supplementary material available at 10.1007/s00203-023-03525-9.

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