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. 1999 Jan;8(1):45–49. doi: 10.1110/ps.8.1.45

Quench-flow experiments combined with mass spectrometry show apomyoglobin folds through and obligatory intermediate.

V Tsui 1, C Garcia 1, S Cavagnero 1, G Siuzdak 1, H J Dyson 1, P E Wright 1
PMCID: PMC2144105  PMID: 10210182

Abstract

Folding of apomyoglobin is characterized by formation of a compact intermediate that contains substantial helicity. To determine whether this intermediate is obligatory or whether the protein can fold directly into the native state via an alternate parallel pathway, we have combined quench-flow hydrogen-exchange pulse labeling techniques with electrospray ionization mass spectrometry. The mass spectra of apomyoglobin obtained at various refolding times suggest that apomyoglobin indeed folds through a single pathway containing an obligatory intermediate with a significant hydrogen-bonded secondary structure content.

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Selected References

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  1. Bryngelson J. D., Wolynes P. G. Spin glasses and the statistical mechanics of protein folding. Proc Natl Acad Sci U S A. 1987 Nov;84(21):7524–7528. doi: 10.1073/pnas.84.21.7524. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Eliezer D., Yao J., Dyson H. J., Wright P. E. Structural and dynamic characterization of partially folded states of apomyoglobin and implications for protein folding. Nat Struct Biol. 1998 Feb;5(2):148–155. doi: 10.1038/nsb0298-148. [DOI] [PubMed] [Google Scholar]
  3. Hughson F. M., Wright P. E., Baldwin R. L. Structural characterization of a partly folded apomyoglobin intermediate. Science. 1990 Sep 28;249(4976):1544–1548. doi: 10.1126/science.2218495. [DOI] [PubMed] [Google Scholar]
  4. Jamin M., Baldwin R. L. Refolding and unfolding kinetics of the equilibrium folding intermediate of apomyoglobin. Nat Struct Biol. 1996 Jul;3(7):613–618. doi: 10.1038/nsb0796-613. [DOI] [PubMed] [Google Scholar]
  5. Jamin M., Baldwin R. L. Two forms of the pH 4 folding intermediate of apomyoglobin. J Mol Biol. 1998 Feb 20;276(2):491–504. doi: 10.1006/jmbi.1997.1543. [DOI] [PubMed] [Google Scholar]
  6. Jennings P. A., Stone M. J., Wright P. E. Overexpression of myoglobin and assignment of its amide, C alpha and C beta resonances. J Biomol NMR. 1995 Nov;6(3):271–276. doi: 10.1007/BF00197808. [DOI] [PubMed] [Google Scholar]
  7. Jennings P. A., Wright P. E. Formation of a molten globule intermediate early in the kinetic folding pathway of apomyoglobin. Science. 1993 Nov 5;262(5135):892–896. doi: 10.1126/science.8235610. [DOI] [PubMed] [Google Scholar]
  8. Katta V., Chait B. T. Conformational changes in proteins probed by hydrogen-exchange electrospray-ionization mass spectrometry. Rapid Commun Mass Spectrom. 1991 Apr;5(4):214–217. doi: 10.1002/rcm.1290050415. [DOI] [PubMed] [Google Scholar]
  9. Kuriyan J., Wilz S., Karplus M., Petsko G. A. X-ray structure and refinement of carbon-monoxy (Fe II)-myoglobin at 1.5 A resolution. J Mol Biol. 1986 Nov 5;192(1):133–154. doi: 10.1016/0022-2836(86)90470-5. [DOI] [PubMed] [Google Scholar]
  10. Mabbutt B. C., Wright P. E. Assignment of heme and distal amino acid resonances in the 1H-NMR spectra of the carbon monoxide and oxygen complexes of sperm whale myoglobin. Biochim Biophys Acta. 1985 Nov 29;832(2):175–185. doi: 10.1016/0167-4838(85)90329-2. [DOI] [PubMed] [Google Scholar]
  11. Miranker A., Robinson C. V., Radford S. E., Aplin R. T., Dobson C. M. Detection of transient protein folding populations by mass spectrometry. Science. 1993 Nov 5;262(5135):896–900. doi: 10.1126/science.8235611. [DOI] [PubMed] [Google Scholar]
  12. Roder H., Elöve G. A., Englander S. W. Structural characterization of folding intermediates in cytochrome c by H-exchange labelling and proton NMR. Nature. 1988 Oct 20;335(6192):700–704. doi: 10.1038/335700a0. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Roder H. Structural characterization of protein folding intermediates by proton magnetic resonance and hydrogen exchange. Methods Enzymol. 1989;176:446–473. doi: 10.1016/0076-6879(89)76024-9. [DOI] [PubMed] [Google Scholar]
  14. Sali A., Shakhnovich E., Karplus M. How does a protein fold? Nature. 1994 May 19;369(6477):248–251. doi: 10.1038/369248a0. [DOI] [PubMed] [Google Scholar]
  15. Sali A., Shakhnovich E., Karplus M. Kinetics of protein folding. A lattice model study of the requirements for folding to the native state. J Mol Biol. 1994 Feb 4;235(5):1614–1636. doi: 10.1006/jmbi.1994.1110. [DOI] [PubMed] [Google Scholar]
  16. Shakhnovich E. I., Gutin A. M. Engineering of stable and fast-folding sequences of model proteins. Proc Natl Acad Sci U S A. 1993 Aug 1;90(15):7195–7199. doi: 10.1073/pnas.90.15.7195. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Udgaonkar J. B., Baldwin R. L. NMR evidence for an early framework intermediate on the folding pathway of ribonuclease A. Nature. 1988 Oct 20;335(6192):694–699. doi: 10.1038/335694a0. [DOI] [PubMed] [Google Scholar]

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