¹⁷O NMR spectroscopy as a tool to study hydrogen bonding of cholesterol in lipid bilayers

Abstract

Solid state NMR of 17O enriched cholesterol in bilayers reveals the chemical shift depends on extent of hydrogen bonding.

Solid-state 17O NMR study of α-d-glucose: exploring new frontiers in isotopic labeling, sensitivity enhancement, and NMR crystallography

“…In general, the values of jC Q ( 17 O)j found in a-D-glucose are about 8-10 MHz with h Q close to 1. These parameters are similar to those previously reported for protected carbohydrate compounds, 25 D-glucosamine, 26 and several other related functional groups such as hemiacetal/hemiketal, 51,52 gem-diol, 53 hydroxyl, 54 and phenolic groups. [55][56][57] Because the six oxygen-containing functional groups in a-Dglucose are very similar, their 17 O isotropic chemical shis, d iso ( 17 O), are found within a small range of 60 ppm.…”

“…The interplay between the two NMR tensors is responsible for the observed field dependence of the static 17 O NMR spectra. From an analysis of these static powder line shapes, we were able to obtain the principal components of the 17 O CS tensor and their relative orientations with respect to the 17 glucosamine, 26 and several other related functional groups such as hemiacetal/hemiketal, 51,52 gem-diol, 53 hydroxyl, 54 and phenolic groups. [55][56][57] Because the six oxygen-containing functional groups in α-D-glucose are very similar, their 17 O isotropic chemical shifts, δ iso ( 17 O), are found within a small range of 60 ppm.…”

Detection of Water Molecules on the Radical Transfer Pathway of Ribonucleotide Reductase by 17O Electron–Nuclear Double Resonance Spectroscopy

“…One key approach for detection of water in biological systems has been the use of 17 O-enriched water in conjunction with magnetic resonance spectroscopy. 16 − 21 Among these methods, electron paramagnetic resonance (EPR) can take advantage of high selectivity, as it detects nuclei only in the ligand sphere ( r ≲ 1.5 nm) 22 of paramagnetic centers.…”

“…Of particular interest is water involvement in electron transfer processes, − its action as a proton wire − or its role in proton-coupled electron transfer (PCET). − The identification of internal water in proteins can be achieved by X-ray diffraction. − However, the crystallization of transient protein complexes is difficult. One key approach for detection of water in biological systems has been the use of 17 O-enriched water in conjunction with magnetic resonance spectroscopy. − Among these methods, electron paramagnetic resonance (EPR) can take advantage of high selectivity, as it detects nuclei only in the ligand sphere ( r ≲ 1.5 nm) of paramagnetic centers.…”

Presence of Cholesterol in Non-Animal Organisms: Identification and Quantification of Cholesterol in Crude Seed Oil from Perilla frutescens and Dehydrated Pyropia tenera

“…Cholesterol is an unsaturated alcohol belonging to the steroid family of compounds [ 1 , 2 ], whose amphiphilic character, imparted by the hydroxyl group (OH), helps to regulate the membrane fluidity of cells [ 3 , 4 ]. It does so by forming hydrogen bonds with water molecules and other lipid components of the cell membrane [ 5 , 6 ]. In the human body, cholesterol is biosynthesized in the liver and is required for the formation of vitamin D and steroid hormones [ 7 , 8 , 9 ].…”