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

Specific binding sites for cations in bacteriorhodopsin.

T Eliash1, L Weiner, M Ottolenghi

  • 1Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.

Biophysical Journal
|July 21, 2001
PubMed
Summary

Cation binding sites in bacteriorhodopsin (bR) were investigated using electron paramagnetic resonance (EPR) spectroscopy. Mn(2+) binding reveals specific extracellular and cytoplasmic sites, influencing bR

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

Emotion Dysregulation in Adults with Acquired Brain Injury: Conceptualization of Emotion Dysregulation, Validation of the French DERS-16 Scale and its Utility in Clinical Practice.

NeuroRehabilitation·2026
Same author

Postnatal cytomegalovirus infection and pulmonary vascular disease in extremely premature infants: A case series.

Journal of neonatal-perinatal medicine·2024
Same author

Compassion-focused therapy (CFT) for the reduction of the self-stigma of mental disorders: the COMpassion for Psychiatric disorders, Autism and Self-Stigma (COMPASS) study protocol for a randomized controlled study.

Trials·2023
Same author

[Anticholinergic scales: Use in psychiatry and update of the anticholinergic impregnation scale].

L'Encephale·2021
Same author

Psychotropics and COVID-19: An analysis of safety and prophylaxis.

L'Encephale·2021
Same author

Panic and pandemic: Narrative review of the literature on the links and risks of panic disorder as a consequence of the SARS-CoV-2 pandemic.

L'Encephale·2020

Area of Science:

  • Biophysics
  • Structural Biology
  • Membrane Proteins

Background:

  • Bacteriorhodopsin (bR) functions as a light-driven proton pump, with Asp-85 residue critical for its function.
  • Protonation of Asp-85 induces a color transition in bR (purple to blue), a process also triggered by cation removal.
  • Previous hypotheses suggested cations bind to the bR surface or internal protein sites, affecting surface pH or retinal vicinity.

Purpose of the Study:

  • To reexamine cation binding mechanisms in bacteriorhodopsin.
  • To determine the location of cation binding sites using electron paramagnetic resonance (EPR) spectroscopy.
  • To elucidate the role of specific cation binding in modulating bR's spectral properties.

Main Methods:

  • Utilized electron paramagnetic resonance (EPR) spectroscopy to study interactions between Mn(2+) and nitroxyl radical probes.

Related Experiment Videos

  • Employed site-directed mutagenesis to introduce cysteine residues for covalent attachment of spin labels.
  • Assessed the effect of Mn(2+) binding on EPR spectra of spin labels at specific positions (74C, 103C, 163C).

    • Main Results:

    • Mn(2+) binding to the highest-affinity site significantly altered the EPR spectrum of a spin label at residue 74C (extracellular side).
    • The distance between the high-affinity binding site and residue 74C was estimated at approximately 9.8 +/- 0.7 Å.
    • Mn(2+) binding to low-affinity sites affected spin labels at residues 103C and 163C (cytoplasmic side), indicating cytoplasmic binding.

    Conclusions:

    • Identified specific cation binding sites on both the extracellular and cytoplasmic sides of bacteriorhodopsin.
    • The highest-affinity cation binding site is located on the extracellular side, near residue 74C.
    • Low-affinity cation binding sites are at least partially on the cytoplasmic side, suggesting involvement of negatively charged lipids on the bR exterior.