Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Probing weakly polar interactions in cytochrome c

D S Auld1, G B Young, A J Saunders

  • 1Department of Chemistry, University of North Carolina at Chapel Hill 27599-3290.

Protein Science : a Publication of the Protein Society
|December 1, 1993
PubMed
Summary

This study investigated sulfur-aromatic interactions in proteins. Replacing phenylalanine with methionine or cysteine analogs showed these interactions are too weak to significantly stabilize protein structure.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Continuous EEG monitoring in the intensive care unit.

Handbook of clinical neurology·2017
Same author

Using electrographic sleep elements to determine outcome of critically ill patients with acute encephalopathy.

European journal of neurology·2014
Same author

Reversible and irreversible cranial MRI findings associated with status epilepticus.

Epilepsy & behavior : E&B·2014
Same author

American Clinical Neurophysiology Society's Standardized Critical Care EEG Terminology: 2012 version.

Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society·2013
Same author

Role of common and rare APP DNA sequence variants in Alzheimer disease.

Neurology·2012
Same author

Disruptions of functional connectivity in the default mode network of comatose patients.

Neurology·2012

Area of Science:

  • Protein structure and stability
  • Biochemistry
  • Molecular biology

Background:

  • Proteins are stabilized by interactions like aromatic-aromatic attractions.
  • Sulfur-containing amino acids (methionine, cysteine) are found in functional protein variants.
  • These variants occur at positions involved in aromatic-aromatic interactions in wild-type proteins.

Purpose of the Study:

  • To investigate if sulfur-aromatic interactions can replace aromatic-aromatic interactions in protein stabilization.
  • To determine the structural and stability effects of introducing sulfur-containing amino acids into specific protein sites.

Main Methods:

  • Proton Nuclear Magnetic Resonance (NMR) spectroscopy to analyze local protein structure.
  • Nuclear Overhauser Effect (NOE) data analysis to assess side-chain positioning.

Related Experiment Videos

  • Calorimetric measurements to determine protein stability (free energy of denaturation).

    • Main Results:

    • Replacing Phenylalanine 10 with Methionine or S-methyl cysteine (CysSMe) resulted in local structural changes only.
    • Sulfur-containing variants maintained nearly identical structures.
    • Both sulfur-containing side chains were positioned to interact with Tyrosine 97.
    • Variants were 2-3 kcal mol-1 less stable than wild-type iso-1-cytochrome c.
    • A minor stability increase in one variant was attributed to hydrophobicity, not sulfur-aromatic interaction.

    Conclusions:

    • Weakly polar sulfur-aromatic interactions are unlikely to be a significant stabilizing force in this protein.
    • Such interactions are either too weak to detect or masked by destabilizing factors.
    • Hydrophobicity plays a more dominant role in the stability of these sulfur-containing variants.