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Volumn 298, Issue 5601, 2002, Pages 2191-2195

Experimental identification of downhill protein folding

Author keywords

[No Author keywords available]

Indexed keywords

CALORIMETRY; ESCHERICHIA COLI; SPECTROSCOPIC ANALYSIS; STATISTICAL METHODS; STRUCTURE (COMPOSITION);

EID: 0037073934     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.1077809     Document Type: Article
Times cited : (279)

References (36)
  • 16
    • 2242479481 scopus 로고    scopus 로고
    • note
    • Materials and methods are available as supplementary material on Science Online.
  • 18
    • 2242491092 scopus 로고    scopus 로고
    • note
    • The differences observed in the thermal unfolding of BBL when monitored by DSC and FRET are not a consequence of the incorporation of the dansyl group in the COOH-terminus of the protein for the FRET experiments. The thermal unfolding of BBL monitored by far-UV CD and analyzed by SVD (Fig. 3) is identical for the two variants of BBL, with and without the dansyl group. This result is further supported by DSC experiments of dansylated BBL in dilute solutions (25 μM) and nondansylated BBL at standard DSC concentrations (0.25 mM). (The higher overall hydrophobicity of dansylated BBL results in high-temperature-induced aggregation at the standard DSC concentrations.
  • 19
    • 2242447280 scopus 로고    scopus 로고
    • note
    • 36. Furthermore, the structure of BBL reveals a partially solvent-exposed hydrophobic core formed by inefficient packing between the two helices. A dansyl group hanging from a partially unfolded COOH-terminal tail can experience transient interactions with this core that will increase its quantum yield by effectively decreasing the average polarizability of its environment. These transient interactions between the dansyl group and the protein are sufficient to perturb its fluorescence quantum yield but do not substantially modify the energetics of BBL's unfolding (18).
  • 23
    • 2242456967 scopus 로고    scopus 로고
    • note
    • 2-and COOH-terminal regions, indicating that the expected α helices are present (fig. S1D). Hδ-Hδ long-range NOEs that correspond to specific tertiary contacts in the native structure are also clearly observed (fig. S1E).
  • 24
    • 2242479480 scopus 로고    scopus 로고
    • note
    • The model applied in this work is very similar to the one described previously by Muñoz & Eaton (32). The main statistical difference lies in the use of residues, instead of peptide bonds, as conformational units. The partition function has been truncated according to the single sequence approximation, as previously described (33). Under this approximation, the number of species in the model reduces to the total number of single stretches of native structure plus the random coil. Each species in the model is identified by two parameters: the position in the sequence of the first native residue and the number of residues in the native stretch [such as (1,40) for the fully native structure]. This approximation is quite accurate for calculating thermodynamic properties.
  • 31
  • 32
    • 0014958182 scopus 로고
    • M. Perutz, Nature 228, 726 (1970).
    • (1970) Nature , vol.228 , pp. 726
    • Perutz, M.1
  • 36
    • 2242451656 scopus 로고    scopus 로고
    • note
    • We thank B. Ibarra-Molero for collaborating in the data analysis and G. Lorimer for helpful suggestions on the manuscript V.M. is a recipient of a Dreyfus New Faculty Award, a Packard Fellowship for Science and Engineering, and a Searle Scholar Award. The research described in this article has been supported in part by grant 36601-AC4 from the Petrol Research Fund (V.M.) and grant BIO2000-1437 from the Spanish Ministry of Science and Technology (J.M.S.R.).


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.