Depolarization Laplace Transform Analysis of Exchangeable Hyperpolarized Xe-129 for Detecting Ordering Phases and Cholesterol Content of Biomembrane Models

作者：Schnurr Matthias; Witte Christopher; Schroeder Leif

来源：Biophysical Journal, 2014, 106(6): 1301-1308.

DOI：10.1016/j.bpj.2014.01.041

We present a highly sensitive nuclear-magnetic resonance technique to study membrane dynamics that combines the temporary encapsulation of spin-hyperpolarized xenon (129Xe) atoms in cryptophane-A-monoacid (CrA(ma)) and their indirect detection through chemical exchange saturation transfer. Radiofrequency-labeled Xe@CrA(ma) complexes exhibit characteristic differences in chemical exchange saturation transfer-driven depolarization when interacting with binary membrane models composed of different molecular ratios of DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) and POPC (1-palmitoy1-2-oleoyl-sn-glycero-3-phosphocholine). The method is also applied to mixtures of cholesterol and POPC. The existence of domains that fluctuate in cluster size in DPPC/POPC models at a high (75-98%) DPPC content induces up to a fivefold increase in spin, depolarization time T at 297 K. In POPC/cholesterol model membranes, the parameter T depends linearly on the cholesterol content at 310 K and allows us to determine the cholesterol content with an accuracy of at least 5%.

• 出版日期2014-3-18