title: A molecular magnet confined in the nanocage of a globular protein.
abstract: The effect of confinement and energy transfer on the dynamics of a molecular magnet, known as a model system to study quantum coherence, is investigated. For this purpose the well-known polyoxovanadate [V(15)As(6)O(42)(H(2)O)](6-) (V(15)) is incorporated into a protein (human serum albumin, HSA) cavity. Due to a huge overlap of the optical absorption spectrum of V(15) with the emission spectrum of a fluorescence center of HSA (containing a single tryptophan residue), energy transfer is induced and probed by steady-state and time-resolved fluorescence. The geometrical coordination and the distance of the confined V(15) to the tryptophan moiety of HSA are investigated at various temperatures. This effect is used as a local probe for the thermal denaturation of the protein at elevated temperatures.
authors.affiliation: Unit for Nano Science and Technology, Department for Chemical, Biological and Macromolecular Sciences, S.N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700098, India.
authors.forename: Rajib K
authors.initials: RK
authors.lastname: Mitra
authors.forename: Pramod K
authors.initials: PK
authors.lastname: Verma
authors.forename: Dirk
authors.initials: D
authors.lastname: Wulferding
authors.forename: Dirk
authors.initials: D
authors.lastname: Menzel
authors.forename: Tamoghna
authors.initials: T
authors.lastname: Mitra
authors.forename: Ana M
authors.initials: AM
authors.lastname: Todea
authors.forename: Peter
authors.initials: P
authors.lastname: Lemmens
authors.forename: Achim
authors.initials: A
authors.lastname: Müller
authors.forename: Samir K
authors.initials: SK
authors.lastname: Pal
mesh_terms: D001665:Binding Sites; D004735:Energy Transfer; D006801:Humans; D008280:Magnetics; D015394:Molecular Structure; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D012709:Serum Albumin / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013696:Temperature; D013816:Thermodynamics
chemical_list: D012709:Serum Albumin