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Titolo:
Molecular-level thermodynamic and kinetic parameters for the self-assemblyof apoferritin molecules into crystals
Autore:
Yau, ST; Petsev, DN; Thomas, BR; Vekilov, PG;
Indirizzi:
Univ Alabama, Dept Chem, Huntsville, AL 35899 USA Univ Alabama HuntsvilleAL USA 35899 Dept Chem, Huntsville, AL 35899 USA Univ Space Res Assoc, George C Marshall Space Flight Ctr, Huntsville, AL 35875 USA Univ Space Res Assoc Huntsville AL USA 35875 tr, Huntsville, AL 35875 USA
Titolo Testata:
JOURNAL OF MOLECULAR BIOLOGY
fascicolo: 5, volume: 303, anno: 2000,
pagine: 667 - 678
SICI:
0022-2836(20001110)303:5<667:MTAKPF>2.0.ZU;2-4
Fonte:
ISI
Lingua:
ENG
Soggetto:
ATOMIC-FORCE MICROSCOPY; TETRAGONAL LYSOZYME CRYSTALS; ELECTRON-MICROSCOPY; STEP DYNAMICS; PROTEIN CRYSTALLIZATION; SURFACE-MORPHOLOGY; GROWTH-MECHANISM; PHASE-BEHAVIOR; TAPPING MODE; 101 FACES;
Keywords:
ferritin; self-assembly; molecular resolution; interaction energy; solvent entropy;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
81
Recensione:
Indirizzi per estratti:
Indirizzo: Vekilov, PG Univ Alabama, Dept Chem, Huntsville, AL 35899 USA Univ Alabama Huntsville AL USA 35899 Huntsville, AL 35899 USA
Citazione:
S.T. Yau et al., "Molecular-level thermodynamic and kinetic parameters for the self-assemblyof apoferritin molecules into crystals", J MOL BIOL, 303(5), 2000, pp. 667-678

Abstract

The self-assembly of apoferritin molecules into crystals is a suitable model for protein crystallization and aggregation; these processes underlie several biological and biomedical phenomena, as well as for protein and virusself-assembly. We use the atomic force microscope in situ, during the crystallization of apoferritin to visualize and quantify at the molecular levelthe processes responsible for crystal growth. To evaluate the governing thermodynamic parameters, we image the configuration of the incorporation sites, "kinks", on the surface of a growing crystal. We show that the kinks are due to thermal fluctuations of the molecules at the crystal-solution interface. This allows evaluation of the free energy of the intermolecular bondphi = 3.0 k(B)T = 7.3 kJ/mol. The crystallization free energy, extracted from the protein solubility, is -42 kJ/mol. Published determinations of the second virial coefficient and the protein solubility between 0 and 40 degreesC revealed that the enthalpy of crystallization is close to zero. Analyses based on these three values suggest that the main component in the crystallization driving force is the entropy gain of the water molecules bound tothe protein molecules in solution and released upon crystallization. Furthermore, monitoring the incorporation of individual molecules in to the kinks, we determine the characteristic frequency of attachment of individual molecules at one set of conditions. This allows a correlation between the mesoscopic kinetic coefficient for growth and the molecular-level thermodynamic and kinetic parameters determined here. We found that step growth velocity, scaled by the molecular size, equals the product of the kink density andattachment frequency, i.e. the latter pair are the molecular-level parameters for self-assembly of the molecules into crystals. (C) 2000 Academic Press.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 26/09/20 alle ore 14:06:30