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 Concept Videos

Energy to Drive Translocation01:37

Energy to Drive Translocation

Mitochondrial protein import is powered by two distinct energy sources: ATP hydrolysis and electrochemical potential across the inner membrane. Newly synthesized precursors are bound by cytosolic chaperones of the Hsp70 family, which guide them to the import receptors on the mitochondrial surface. Utilizing the energy of ATP hydrolysis, Hsp70 chaperones transfer these precursors to the TOM receptors on the mitochondrial outer membrane.
Generally, polypeptides are unfolded by two distinct...
Protein Transport to the Thylakoids01:22

Protein Transport to the Thylakoids

Thylakoids are membrane-bound sac-like structures within the chloroplast that serve as sites for photosynthesis. Thylakoid lumen contains many electron transport proteins and is enclosed by a thylakoid membrane rich in the light-harvesting complex. Proteins targeted to the thylakoids are transported as precursors and are sorted by the general TOC/TIC import pathway. Once the precursor reaches the stroma, stromal processing peptidases remove their transit signal and expose thylakoid signal...
Protein Transport into the Inner Mitochondrial Membrane01:34

Protein Transport into the Inner Mitochondrial Membrane

Nuclear encoded mitochondrial precursors are imported to the inner membrane in a multistep process involving two separate translocons, TIM22 and TIM23. TIM23 is a cation-selective pore that remains closed by the N terminal segment of the protein. Negative charges on the TIM23 act as a receptor for the incoming precursor, pulling the positively charged matrix-targeting sequence for peptide insertion and translocation.
Transport of mitochondrial precursors across the TIM23 channel is driven by...
Protein-protein Interfaces02:04

Protein-protein Interfaces

Many proteins form complexes to carry out their functions, making protein-protein interactions (PPIs) essential for an organism's survival. Most PPIs are stabilized by numerous weak noncovalent chemical forces. The physical shape of the interfaces determines the way two proteins interact. Many globular proteins have closely-matching shapes on their surfaces, which form a large number of weak bonds. Additionally, many PPIs occur between two helices or between a surface cleft and a polypeptide...
Protein-Protein Interfaces02:04

Protein-Protein Interfaces

Many proteins form complexes to carry out their functions, making protein-protein interactions (PPIs) essential for an organism's survival. Most PPIs are stabilized by numerous weak noncovalent chemical forces. The physical shape of the interfaces determines the way two proteins interact. Many globular proteins have closely-matching shapes on their surfaces, which form a large number of weak bonds. Additionally, many PPIs occur between two helices or between a surface cleft and a polypeptide...
Cotranslational Protein Translocation01:20

Cotranslational Protein Translocation

Translocation of proteins across membranes is an ancient process that occurs even in bacteria and archaebacteria. In fact, the components of the translocation machinery are still conserved between prokaryotes and eukaryotes.
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...

You might also read

Related Articles

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

Sort by
Same author

Multistep electron tunneling through tryptophans in the KatG bifunctional peroxidase monitored by a nonperturbing spin probe.

Proceedings of the National Academy of Sciences of the United States of America·2026
Same author

When TiO<sub>2</sub> meets pharmaceuticals: Photocatalytic degradation and environmental safety unveiled.

Ecotoxicology and environmental safety·2026
Same author

Evaluation of a human 3D multi-spheroid model derived from SH-SY5Y cells for cytotoxicity testing.

Scientific reports·2026
Same author

Site-Selective C-H Functionalization on Coumarins Directed by Manganese: Mechanistic Insights from Time-Resolved Spectroscopy and Catalytic Development.

ACS organic & inorganic Au·2026
Same author

Femtosecond-to-Second Time-Resolved Spectroscopy Brings Unparalleled Insight Into the Life Cycle of the Versatile Manganese Photocatalyst [Mn<sub>2</sub>(CO)<sub>10</sub>].

Journal of the American Chemical Society·2026
Same author

Laurdan: Clarifying Photophysics and Advancing the Characterization of Extracellular Vesicles.

Chemphyschem : a European journal of chemical physics and physical chemistry·2026

Related Experiment Video

Updated: May 7, 2026

PCR Mutagenesis, Cloning, Expression, Fast Protein Purification Protocols and Crystallization of the Wild Type and Mutant Forms of Tryptophan Synthase
09:31

PCR Mutagenesis, Cloning, Expression, Fast Protein Purification Protocols and Crystallization of the Wild Type and Mutant Forms of Tryptophan Synthase

Published on: September 26, 2020

Tryptophan-accelerated electron flow across a protein-protein interface.

Kana Takematsu1, Heather Williamson, Ana María Blanco-Rodríguez

  • 1Beckman Institute, California Institute of Technology , Pasadena, California 91125, United States.

Journal of the American Chemical Society
|September 17, 2013
PubMed
Summary
This summary is machine-generated.

This study reveals that protein dimers accelerate electron transfer (ET) via interfacial tryptophan hopping. This hopping mechanism, observed in metallolabeled azurin, is crucial for long-range charge separation in protein complexes.

More Related Videos

Chemical Modification of the Tryptophan Residue in a Recombinant Ca2+-ATPase N-domain for Studying Tryptophan-ANS FRET
12:07

Chemical Modification of the Tryptophan Residue in a Recombinant Ca2+-ATPase N-domain for Studying Tryptophan-ANS FRET

Published on: October 9, 2021

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy
10:03

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy

Published on: June 27, 2014

Related Experiment Videos

Last Updated: May 7, 2026

PCR Mutagenesis, Cloning, Expression, Fast Protein Purification Protocols and Crystallization of the Wild Type and Mutant Forms of Tryptophan Synthase
09:31

PCR Mutagenesis, Cloning, Expression, Fast Protein Purification Protocols and Crystallization of the Wild Type and Mutant Forms of Tryptophan Synthase

Published on: September 26, 2020

Chemical Modification of the Tryptophan Residue in a Recombinant Ca2+-ATPase N-domain for Studying Tryptophan-ANS FRET
12:07

Chemical Modification of the Tryptophan Residue in a Recombinant Ca2+-ATPase N-domain for Studying Tryptophan-ANS FRET

Published on: October 9, 2021

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy
10:03

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy

Published on: June 27, 2014

Area of Science:

  • Biochemistry
  • Biophysics
  • Protein Engineering

Background:

  • Blue copper proteins like azurin are vital electron transfer agents.
  • Understanding long-range electron transfer (ET) in proteins is key to bioenergetics.
  • Metallolabeling provides a tool to probe ET pathways within proteins.

Purpose of the Study:

  • To investigate photoinduced electron transfer in a novel metallolabeled azurin.
  • To elucidate the role of protein interfaces and tryptophan in mediating ET.
  • To determine optimal redox-unit placement for efficient charge separation.

Main Methods:

  • Site-specific covalent attachment of a rhenium (Re) complex to azurin at H126.
  • Spectroscopic analysis (UV-Vis absorption, fluorescence) to monitor ET kinetics.
  • Solution mass spectrometry and X-ray crystallography to characterize protein oligomerization and structure.

Main Results:

  • A metallolabeled azurin, Re126W122Cu(I), was created with three redox sites (Re, W122 indole, Cu).
  • Photoexcitation of the Re chromophore induced rapid Cu(I) oxidation (<50 ns).
  • Electron transfer occurred primarily in protein dimers, facilitated by intermolecular tryptophan hopping at the interface, accelerating forward ET but retarding back ET.

Conclusions:

  • Protein-protein interfaces can significantly influence and optimize electron transfer rates.
  • Interfacial electron hopping through tryptophan residues is a viable mechanism for long-range charge separation.
  • This work provides insights into designing protein-based systems for efficient charge transfer applications.