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

Protein Diffusion in the Membrane01:24

Protein Diffusion in the Membrane

6.0K
Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...
6.0K
Overview of Protein Sorting and Transport01:45

Overview of Protein Sorting and Transport

23.2K
Eukaryotic cells have different membrane-bound organelles with distinct protein requirements. The process by which proteins are targeted to a specific organelle is called protein sorting.
Protein sorting can be of two types: signal-based sorting and vesicle-based trafficking. In signal-based sorting, specific amino acid sequences called sorting signals target proteins to the proper location inside the cell either via gated transport or by protein translocation.  In gated transport, folded...
23.2K
Protein Dynamics in Living Cells01:19

Protein Dynamics in Living Cells

2.8K
Different fluorescence-based techniques are used to study the protein dynamics in living cells. These techniques include FRAP, FRET, and PET.
Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached...
2.8K
Regulated mRNA Transport02:22

Regulated mRNA Transport

7.1K
In eukaryotes, transcription and translation are compartmentalized; an mRNA is first synthesized in the nucleus and then selectively transported to the cytoplasm for protein synthesis. Before transport, a pre-mRNA undergoes several steps of post-transcriptional modifications including splicing, 5' capping, and the addition of a poly-adenine tail. Various proteins bind to the pre-mRNA during these modifications. The mRNA transport takes place with the help of multiple proteins playing...
7.1K
Post-translational Translocation of Proteins to the RER01:27

Post-translational Translocation of Proteins to the RER

7.9K
A sizable fraction of proteins destined for ER are first synthesized in the cell cytosol and then transported across the ER membrane–a process called post-translational translocation. Similar to cotranslationally translocated proteins, these proteins also use the Sec translocon complex to enter the ER lumen.
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...
7.9K
Subcellular Fractionation01:32

Subcellular Fractionation

9.0K
The homogenate obtained after cell lysis contains various membrane-bound organelles that can be further separated into pure fractions by subcellular fractionation. These isolates are used to study specific cellular components, analyze localized protein activity, and are even employed in diagnostics. Fractionation is typically achieved using centrifugation methods, the most common being density-gradient and differential centrifugation.
Differential Centrifugation
Differential centrifugation is...
9.0K

You might also read

Related Articles

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

Sort by
Same author

<i>Staphylococcus</i> species infected by a bacteriophage with a tail that is both curved and contractile.

mBio·2026
Same author

Understanding the dynamics of Pseudomonas syringae tailocin targeting allows for predictive protective microbial inoculation of Actinidia chinensis.

Microbiological research·2025
Same author

Chemical inhibition of MrkH-dependent activation of type 3 fimbriae synthesis and biofilm formation by Klebsiella pneumoniae.

NPJ biofilms and microbiomes·2025
Same author

Highly stable bacteriophages PIN1 and PIN2 have hallmarks of flagellotropic phages but infect immotile bacteria.

Npj viruses·2025
Same author

Telomere bacteriophages are widespread and equip their bacterial hosts with potent interbacterial weapons.

Science advances·2025
Same author

Ethical bioprospecting and microbial assessments for sustainable solutions to the AMR crisis.

IUBMB life·2024

Related Experiment Video

Updated: Feb 27, 2026

Density Gradient Ultracentrifugation for Investigating Endocytic Recycling in Mammalian Cells
05:13

Density Gradient Ultracentrifugation for Investigating Endocytic Recycling in Mammalian Cells

Published on: June 30, 2021

4.9K

Defining Membrane Protein Localization by Isopycnic Density Gradients.

Rhys A Dunstan1, Iain D Hay1, Trevor Lithgow2

  • 1Department of Microbiology and Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, VIC, Melbourne, 3800, Australia.

Methods in Molecular Biology (Clifton, N.J.)
|July 2, 2017
PubMed
Summary

This study details a method for isolating bacterial membranes and their proteins. The protocol is effective for Escherichia coli and adaptable for other bacterial species, aiding membrane protein research.

Keywords:
Beta-barrel proteinsCytoplasmic membraneLipoproteinsMembrane biogenesisSucrose density gradient

More Related Videos

Preparation of Synaptic Plasma Membrane and Postsynaptic Density Proteins Using a Discontinuous Sucrose Gradient
08:06

Preparation of Synaptic Plasma Membrane and Postsynaptic Density Proteins Using a Discontinuous Sucrose Gradient

Published on: September 3, 2014

32.1K
Brain Membrane Fractionation: An Ex Vivo Approach to Assess Subsynaptic Protein Localization
09:49

Brain Membrane Fractionation: An Ex Vivo Approach to Assess Subsynaptic Protein Localization

Published on: May 12, 2017

10.8K

Related Experiment Videos

Last Updated: Feb 27, 2026

Density Gradient Ultracentrifugation for Investigating Endocytic Recycling in Mammalian Cells
05:13

Density Gradient Ultracentrifugation for Investigating Endocytic Recycling in Mammalian Cells

Published on: June 30, 2021

4.9K
Preparation of Synaptic Plasma Membrane and Postsynaptic Density Proteins Using a Discontinuous Sucrose Gradient
08:06

Preparation of Synaptic Plasma Membrane and Postsynaptic Density Proteins Using a Discontinuous Sucrose Gradient

Published on: September 3, 2014

32.1K
Brain Membrane Fractionation: An Ex Vivo Approach to Assess Subsynaptic Protein Localization
09:49

Brain Membrane Fractionation: An Ex Vivo Approach to Assess Subsynaptic Protein Localization

Published on: May 12, 2017

10.8K

Area of Science:

  • Microbiology
  • Cell Biology
  • Biochemistry

Background:

  • Bacterial membrane proteins constitute a significant portion of cellular mass and function.
  • Characterizing these proteins is crucial for understanding bacterial physiology and developing therapeutics.

Purpose of the Study:

  • To present a reproducible protocol for purifying bacterial outer and inner membranes.
  • To enable detailed analysis of membrane protein composition and function.

Main Methods:

  • Isolation of bacterial envelopes from Escherichia coli.
  • Differential solubilization and ultracentrifugation techniques to separate inner and outer membranes.
  • Assessment of membrane purity and protein integrity.

Main Results:

  • Successfully purified distinct outer and inner membrane fractions from Escherichia coli.
  • The protocol demonstrated high yield and purity of membrane components.
  • The method showed adaptability for bacteria with complex outer membrane structures.

Conclusions:

  • The described protocol provides a robust method for bacterial membrane and membrane protein purification.
  • This technique facilitates further investigation into bacterial membrane biology.
  • The adaptability of the protocol broadens its applicability across diverse bacterial species.