NMR studies of lysozyme surface accessibility by using different paramagnetic relaxation probes

Andrea Bernini, Ottavia Spiga, Vincenzo Venditti, Filippo Prischi, Luisa Bracci, Angela Pui Ling Tong, Wing Tak Wong, Neri Niccolai

Research output: Journal article publicationJournal articleAcademic researchpeer-review

27 Citations (Scopus)

Abstract

Paramagnetic probes, whose approach to proteins can be monitored by nuclear magnetic resonance (NMR) studies, have been found to be of primary relevance for investigating protein surfaces' accessibility. Here, a Gd(III) neutral complex which contains two metal ions, [Gd2(L7)(H2O)2], is suggested as a paramagnetic probe particularly suited for systematic NMR investigation of protein surface accessibility, due to an expected high relaxivity and to the lack of electric charge which could favor specific interactions. Hen egg white lysozyme has been used as a model system to verify the absence of preferential approaches of this paramagnetic probe to specific protein moieties by comparing paramagnetic perturbation profiles of1H-13C HSQC signals obtained in the presence of TEMPOL and [Gd2(L7)(H2O)2]. From the similarity of the measured paramagnetic perturbation profiles induced by the two different probes, specific interactions of [Gd2(L7)(H2O)2]with the enzyme could be ruled out. The large size of the latter probe is suggested to be responsible for the strong paramagnetic perturbations observed for CαH groups which are located in convex surface-exposed regions. The combined use of the two probes reveals fine details of the dynamics controlling their approach toward the protein surface.
Original languageEnglish
Pages (from-to)9290-9291
Number of pages2
JournalJournal of the American Chemical Society
Volume128
Issue number29
DOIs
Publication statusPublished - 26 Jul 2006
Externally publishedYes

ASJC Scopus subject areas

  • Chemistry(all)

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