ERBB2 recombinant proteins are engineered versions of the ERBB2 protein, also known as HER2 (Human Epidermal Growth Factor Receptor 2). ERBB2 is a receptor tyrosine kinase involved in cell growth and differentiation, and it is notably overexpressed in various cancers, including breast and ovarian cancers. Recombinant ERBB2 proteins are essential in cancer research, diagnostics, and therapeutic development.

Structure and Function

• ERBB2 is a member of the EGFR (Epidermal Growth Factor Receptor) family of receptor tyrosine kinases. It has an extracellular ligand-binding domain, a transmembrane domain, and an intracellular tyrosine kinase domain.
• Unlike other EGFR family members, ERBB2 does not have a known ligand; instead, it acts as a co-receptor, forming heterodimers with other EGFR family members to activate downstream signaling pathways involved in cell proliferation and survival.
• The overexpression or amplification of ERBB2 is associated with aggressive tumor growth, making it a critical target in oncology.

Production

• ERBB2 recombinant proteins are produced using various expression systems, including mammalian cells, insect cells, or yeast, to achieve proper folding and post-translational modifications, such as glycosylation.
• The production process involves cloning the gene encoding the extracellular domain or full-length ERBB2 into an expression vector, followed by expression and purification using affinity chromatography (e.g., His-tag or Fc-tag).

Applications

• Cancer Research: Recombinant ERBB2 proteins are used to study the signaling pathways activated by HER2 and its role in cancer progression, particularly in breast and ovarian cancers.
• Therapeutic Development: These proteins are employed in screening assays to develop and test monoclonal antibodies (e.g., trastuzumab) and small-molecule inhibitors targeting HER2.
• Diagnostics: ERBB2 recombinant proteins are used in diagnostic assays to detect HER2 overexpression in tumor tissues, guiding the use of targeted therapies in cancer treatment.
• Immunoassays: They serve as antigens in ELISA and other immunoassays to detect HER2-specific antibodies in research and clinical settings.

Validation and Quality Control

• Validation involves confirming the identity, purity, and functionality of recombinant ERBB2 proteins using techniques like SDS-PAGE, Western blotting, and mass spectrometry.
• Functional assays, such as kinase activity assays or binding assays with monoclonal antibodies, ensure that the recombinant proteins are biologically active and suitable for their intended applications.