Data di Pubblicazione:
2014
Citazione:
Synthesis, Characterization and Applications of a Perdeuterated Amphipol / F. Giusti, J. Rieger, L.J. Catoire, S. Qian, A.N. Calabrese, T.G. Watkinson, M. Casiraghi, S.E. Radford, A.E. Ashcroft, J. Popot. - In: THE JOURNAL OF MEMBRANE BIOLOGY. - ISSN 0022-2631. - 247:9-10(2014 Oct), pp. 909-924. [10.1007/s00232-014-9656-x]
Abstract:
Amphipols are short amphipathic polymers that can substitute for detergents at the hydrophobic surface of membrane proteins (MPs), keeping them soluble in the absence of detergents while stabilizing them. The most widely used amphipol, known as A8-35, is comprised of a polyacrylic acid (PAA) main chain grafted with octylamine and isopropylamine. Among its many applications, A8-35 has proven particularly useful for solution-state NMR studies of MPs, for which it can be desirable to eliminate signals originating from the protons of the surfactant. In the present work, we describe the synthesis and properties of perdeuterated A8-35 (perDAPol). Perdeuterated PAA was obtained by radical polymerization of deuterated acrylic acid. It was subsequently grafted with deuterated amines, yielding perDAPol. The number-average molar mass of hydrogenated and perDAPol, similar to 4 and similar to 5 kDa, respectively, was deduced from that of their PAA precursors, determined by size exclusion chromatography in tetrahydrofuran following permethylation. Electrospray ionization-ion mobility spectrometry-mass spectrometry measurements show the molar mass and distribution of the two APols to be very similar. Upon neutron scattering, the contrast match point of perDAPol is found to be similar to 120 % D2O. In H-1-H-1 nuclear overhauser effect NMR spectra, its contribution is reduced to similar to 6 % of that of hydrogenated A8-35, making it suitable for extended uses in NMR spectroscopy. PerDAPol ought to also be of use for inelastic neutron scattering studies of the dynamics of APol-trapped MPs, as well as small-angle neutron scattering and analytical ultracentrifugation.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Amphipol; A8-35; Deuteration; Mass spectrometry; NMR
Elenco autori:
F. Giusti, J. Rieger, L.J. Catoire, S. Qian, A.N. Calabrese, T.G. Watkinson, M. Casiraghi, S.E. Radford, A.E. Ashcroft, J. Popot
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