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Mechanical and chemical unfolding of a single protein: a comparison.

Publication ,  Journal Article
Carrion-Vazquez, M; Oberhauser, AF; Fowler, SB; Marszalek, PE; Broedel, SE; Clarke, J; Fernandez, JM
Published in: Proceedings of the National Academy of Sciences of the United States of America
March 1999

Is the mechanical unraveling of protein domains by atomic force microscopy (AFM) just a technological feat or a true measurement of their unfolding? By engineering a protein made of tandem repeats of identical Ig modules, we were able to get explicit AFM data on the unfolding rate of a single protein domain that can be accurately extrapolated to zero force. We compare this with chemical unfolding rates for untethered modules extrapolated to 0 M denaturant. The unfolding rates obtained by the two methods are the same. Furthermore, the transition state for unfolding appears at the same position on the folding pathway when assessed by either method. These results indicate that mechanical unfolding of a single protein by AFM does indeed reflect the same event that is observed in traditional unfolding experiments. The way is now open for the extensive use of AFM to measure folding reactions at the single-molecule level. Single-molecule AFM recordings have the added advantage that they define the reaction coordinate and expose rare unfolding events that cannot be observed in the absence of chemical denaturants.

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Published In

Proceedings of the National Academy of Sciences of the United States of America

DOI

EISSN

1091-6490

ISSN

0027-8424

Publication Date

March 1999

Volume

96

Issue

7

Start / End Page

3694 / 3699

Related Subject Headings

  • Repetitive Sequences, Amino Acid
  • Protein Kinases
  • Protein Folding
  • Protein Engineering
  • Protein Denaturation
  • Polymerase Chain Reaction
  • Myocardium
  • Muscle Proteins
  • Microscopy, Atomic Force
  • Humans
 

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Carrion-Vazquez, M., Oberhauser, A. F., Fowler, S. B., Marszalek, P. E., Broedel, S. E., Clarke, J., & Fernandez, J. M. (1999). Mechanical and chemical unfolding of a single protein: a comparison. Proceedings of the National Academy of Sciences of the United States of America, 96(7), 3694–3699. https://doi.org/10.1073/pnas.96.7.3694
Carrion-Vazquez, M., A. F. Oberhauser, S. B. Fowler, P. E. Marszalek, S. E. Broedel, J. Clarke, and J. M. Fernandez. “Mechanical and chemical unfolding of a single protein: a comparison.Proceedings of the National Academy of Sciences of the United States of America 96, no. 7 (March 1999): 3694–99. https://doi.org/10.1073/pnas.96.7.3694.
Carrion-Vazquez M, Oberhauser AF, Fowler SB, Marszalek PE, Broedel SE, Clarke J, et al. Mechanical and chemical unfolding of a single protein: a comparison. Proceedings of the National Academy of Sciences of the United States of America. 1999 Mar;96(7):3694–9.
Carrion-Vazquez, M., et al. “Mechanical and chemical unfolding of a single protein: a comparison.Proceedings of the National Academy of Sciences of the United States of America, vol. 96, no. 7, Mar. 1999, pp. 3694–99. Epmc, doi:10.1073/pnas.96.7.3694.
Carrion-Vazquez M, Oberhauser AF, Fowler SB, Marszalek PE, Broedel SE, Clarke J, Fernandez JM. Mechanical and chemical unfolding of a single protein: a comparison. Proceedings of the National Academy of Sciences of the United States of America. 1999 Mar;96(7):3694–3699.
Journal cover image

Published In

Proceedings of the National Academy of Sciences of the United States of America

DOI

EISSN

1091-6490

ISSN

0027-8424

Publication Date

March 1999

Volume

96

Issue

7

Start / End Page

3694 / 3699

Related Subject Headings

  • Repetitive Sequences, Amino Acid
  • Protein Kinases
  • Protein Folding
  • Protein Engineering
  • Protein Denaturation
  • Polymerase Chain Reaction
  • Myocardium
  • Muscle Proteins
  • Microscopy, Atomic Force
  • Humans