Related Experiment Video

Updated: May 28, 2026

Assessing Cellular Target Engagement by SHP2 (PTPN11) Phosphatase Inhibitors
08:45

Assessing Cellular Target Engagement by SHP2 (PTPN11) Phosphatase Inhibitors

Published on: July 17, 2020

Conformation-sensing antibodies stabilize the oxidized form of PTP1B and inhibit its phosphatase activity

Aftabul Haque1, Jannik N Andersen, Annette Salmeen

  • 1Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.

Cell
|October 4, 2011
PubMed

Insights

Researchers developed novel antibodies to stabilize the inactive form of Protein tyrosine phosphatase 1B (PTP1B), offering a new therapeutic strategy for diabetes and obesity by enhancing insulin signaling.

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Pharmacology

Background:

  • Protein tyrosine phosphatase 1B (PTP1B) is a key regulator of insulin and leptin signaling pathways.
  • PTP1B activity is modulated by reactive oxygen species (ROS), with its oxidized form (PTP1B-OX) being inactive.
  • PTP1B is a significant therapeutic target for metabolic disorders like diabetes and obesity.

Purpose of the Study:

  • To develop novel therapeutic agents targeting PTP1B.
  • To investigate the potential of stabilizing the inactive, oxidized form of PTP1B (PTP1B-OX) for therapeutic benefit.

Main Methods:

  • Generation of conformation-sensor single-chain variable fragments (scFvs) designed to specifically bind and stabilize PTP1B-OX.
  • Expression of these scFvs as intracellular antibodies (intrabodies) within cells.
  • Assessment of the impact on insulin signaling pathways, including insulin receptor and IRS-1 phosphorylation, and PKB/AKT activation.

Main Results:

  • Conformation-sensor scFvs successfully stabilized the inactive PTP1B-OX form.
  • Intracellular expression of scFvs enhanced insulin-induced tyrosyl phosphorylation of the insulin receptor β subunit and IRS-1.
  • Increased insulin-induced phosphorylation of PKB/AKT was observed, indicating enhanced insulin signaling.

Conclusions:

  • Stabilizing the oxidized, inactive form of PTP1B using specific molecules like scFvs is a viable strategy.
  • This approach offers a novel paradigm for the development of phosphatase-targeted drugs for metabolic diseases.
  • Intrabody technology presents a promising method for modulating enzyme activity intracellularly.

More Related Videos

Co-immunoprecipitation Assay for Studying Functional Interactions Between Receptors and Enzymes09:40

Co-immunoprecipitation Assay for Studying Functional Interactions Between Receptors and Enzymes

Published on: September 28, 2018

Identification of Post-translational Modifications of Plant Protein Complexes10:07

Identification of Post-translational Modifications of Plant Protein Complexes

Published on: February 22, 2014

Related Concept Videos

Allosteric Proteins-ATCase01:19

Allosteric Proteins-ATCase

Binding sites linkages can regulate a protein's function.  For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to  N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Amplifying Signals via Enzymatic Cascade01:22

Amplifying Signals via Enzymatic Cascade

When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the...
Covalently Linked Protein Regulators02:04

Covalently Linked Protein Regulators

Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
Phosphoinositides and PIPs01:42

Phosphoinositides and PIPs

Phosphoinositides are a group of phospholipids containing a glycerol backbone with two fatty acid chains and a phosphate attached to a myoinositol sugar ring. The inositol head group extends into the cytoplasm, where it is modified by adding phosphate groups to form phosphatidylinositol phosphates or PIPs.
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...
Protein Kinases and Phosphatases02:54

Protein Kinases and Phosphatases

Proteins undergo chemical modifications that trigger changes in the charge, structure, and conformation of the proteins. Phosphorylation, acetylation, glycosylation, nitrosylation, ubiquitination, lipidation, methylation, and proteolysis are various protein modifications that regulate protein activity. Such modifications are usually enzyme-driven.
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Phosphorylation01:02

Phosphorylation

The addition or removal of phosphate groups from proteins is the most common chemical modification that regulates cellular processes. These modifications can affect the structure, activity, stability, and localization of proteins within cells as well as their interactions with other proteins.
During phosphorylation, protein kinases transfer the terminal phosphate group of ATP to specific amino acid side chains of substrate proteins. Serine, threonine, and tyrosine are the most commonly...