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

Ligand Binding Sites02:40

Ligand Binding Sites

Proteins are dynamic macromolecules that carry out a wide variety of essential processes; however, the activities of most proteins depend on their interactions with other molecules or ions, known as ligands.
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
Ligand Binding and Linkage00:49

Ligand Binding and Linkage

Allosteric proteins have more than one ligand binding site; the binding of a ligand to any of these sites influences the binding of ligands to the other sites. When a protein is allosteric, its binding sites are called coupled or linked.  In the case of enzymes, the site that binds to the substrate is known as the active site and the other site is known as the regulatory site. When a ligand binds to the regulatory site, this leads to conformational changes in the protein that can influence the...
Protein Complexes with Interchangeable Parts01:57

Protein Complexes with Interchangeable Parts

Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
Selectins01:25

Selectins

Cell adhesion is  an essential aspect of multicellularity. While stable cell interactions usually occur between cells of the same type, transient cell interactions occur between cells of different tissue types, such as between neutrophils and endothelial cells. Selectins are one class of cell adhesion molecules (CAMs) that bind carbohydrate ligands to form transient cell adhesion. They are rod-like proteins with a long extracellular part of variable length ending with the lectin domain, which...
Immunoglobulin-like Cell Adhesion Molecules01:31

Immunoglobulin-like Cell Adhesion Molecules

Immunoglobulin-like cell adhesion molecules or Ig-CAMs are a versatile group of cell surface glycoproteins belonging to the immunoglobulin protein superfamily. Ig-CAMs possess the characteristic immunoglobulin protein domains and other domains such as the fibronectin type III domain. The Ig domains are glycosylated to varying degrees in different Ig-CAMs.
Ig-CAMs exhibit either homophilic binding (to other Ig-CAMs) or heterophilic binding (to other ligands such as integrins). While most Ig-CAMs...
Diversity of Antigen Receptors01:28

Diversity of Antigen Receptors

Antigen receptors are essential components of the immune system crucial in defending the body against foreign invaders. These receptors are present on the surface of B and T cells, enabling them to recognize antigens and mount an appropriate immune response.
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...

You might also read

Related Articles

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

Sort by
Same author

Purification of post-transcriptionally modified tRNAs for enhanced cell-free translation systems.

Nucleic acids research·2026
Same author

Co-Translational Incorporation of <i>(R)</i>- and <i>(S)</i>-β<sup>2</sup>-Hydroxy Acids <i>In Vitro</i>: A Structural and Biochemical Study on the <i>E. coli</i> Ribosome.

Journal of the American Chemical Society·2026
Same author

Co-Translational Incorporation of (<i>R</i>)- and (<i>S</i>)-β<sup>2</sup>-Hydroxyacids <i>In Vivo</i>: Directed Evolution of Efficient Aminoacyl-tRNA Synthetases.

Journal of the American Chemical Society·2026
Same author

Expanding the multiplexing capability of HIDE probes via fluorescence lifetime imaging microscopy.

Methods in enzymology·2026
Same author

A clickable CoQ imaging probe reveals that cellular uptake and lysosomal trafficking depend on CD36 and NPC1.

Redox biology·2026
Same author

An archaeal genetic code with all TAG codons as pyrrolysine.

Science (New York, N.Y.)·2025

Related Experiment Video

Updated: Jul 10, 2026

Examining BCL-2 Family Function with Large Unilamellar Vesicles
08:35

Examining BCL-2 Family Function with Large Unilamellar Vesicles

Published on: October 5, 2012

Paralog-selective ligands for bcl-2 proteins.

Anja C Gemperli1, Stacey E Rutledge, Abby Maranda

  • 1Departments of Chemistry and Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520, USA.

Journal of the American Chemical Society
|February 11, 2005
PubMed
Summary

Researchers engineered miniature proteins, PPBH3-5 and PPBH3-6, to selectively bind Bcl-2 proteins over Bcl-XL. These novel nonnatural ligands offer new tools for inhibiting specific protein-protein interactions.

More Related Videos

Identifying Protein-protein Interaction Sites Using Peptide Arrays
07:44

Identifying Protein-protein Interaction Sites Using Peptide Arrays

Published on: November 18, 2014

Selecting Multiple Biomarker Subsets with Similarly Effective Binary Classification Performances
07:35

Selecting Multiple Biomarker Subsets with Similarly Effective Binary Classification Performances

Published on: October 11, 2018

Related Experiment Videos

Last Updated: Jul 10, 2026

Examining BCL-2 Family Function with Large Unilamellar Vesicles
08:35

Examining BCL-2 Family Function with Large Unilamellar Vesicles

Published on: October 5, 2012

Identifying Protein-protein Interaction Sites Using Peptide Arrays
07:44

Identifying Protein-protein Interaction Sites Using Peptide Arrays

Published on: November 18, 2014

Selecting Multiple Biomarker Subsets with Similarly Effective Binary Classification Performances
07:35

Selecting Multiple Biomarker Subsets with Similarly Effective Binary Classification Performances

Published on: October 11, 2018

Area of Science:

  • Molecular biology
  • Protein engineering
  • Biochemistry

Background:

  • Miniature proteins based on pancreatic-fold polypeptides can bind protein surfaces and inhibit protein-protein interactions.
  • Previous work demonstrated high affinity and selectivity of such proteins for shallow alpha-helix binding clefts.
  • A miniature protein, PPBH3-1, selectively binds Bcl-2 and Bcl-XL with a preference for Bcl-XL.

Purpose of the Study:

  • To engineer new miniature proteins with reversed paralog specificity compared to PPBH3-1.
  • To develop ligands that selectively target Bcl-2 over Bcl-XL.
  • To explore the mechanisms of achieving high paralog specificity in miniature protein design.

Main Methods:

  • Directed evolution of the PPBH3-1 miniature protein.
  • Affinity and selectivity measurements using techniques like DeltaDeltaG.
  • Experiments with Bcl-XL variants to probe molecular interactions.

Main Results:

  • Two new miniature proteins, PPBH3-5 and PPBH3-6, were successfully evolved.
  • PPBH3-5 and PPBH3-6 exhibit nanomolar affinity for Bcl-2, with a preference for Bcl-2 over Bcl-XL (DeltaDeltaG = 0.9-1.3 kcal.mol-1).
  • These proteins likely exploit subtle structural or electrostatic differences between Bcl-2 and Bcl-XL.

Conclusions:

  • PPBH3-5 and PPBH3-6 represent novel miniature proteins with reversed paralog specificity.
  • These engineered proteins demonstrate selective interaction with Bcl-2 proteins.
  • They serve as early examples of nonnatural ligands with potential applications in targeting Bcl-2 family proteins.