Beta-galactosidase Enzyme Acceptor – Catalog #: P2010005 (1 mg)

About β-Galactosidase Alpha Complementation

β-Galactosidase alpha complementation is a classic phenomenon described in the Jacob–Monod laboratory (with key contributions by Agnes Ullmann). Through molecular cloning, the native E. coli β-galactosidase can be expressed as two inactive fragments: a small N-terminal alpha fragment (also called the enzyme donor) and a larger omega fragment (enzyme acceptor). Individually, these fragments show no measurable enzymatic activity on β-gal substrates; when combined, they reconstitute functional β-galactosidase capable of hydrolyzing common colorimetric substrates.

In research workflows, pairing the enzyme donor with the enzyme acceptor enables assay formats in which complementation is coupled to an interaction of interest (for example, via an antibody). Because activity appears only upon fragment association, these systems can support qualitative readouts while helping manage background prior to complementation. This page provides the acceptor/donor components for assembling such alpha-complementation methods in research settings.

Beta-galactosidase Enzyme Acceptor (also called the Omega peptide) is the larger fragment of the E. coli β-galactosidase enzyme that reconstitutes full activity when combined with the complementary Alpha peptide (enzyme donor). The Molecular Depot listing specifies a 1.0 mg fill (Catalog P2010005), supplied as a white lyophilized powder with a reported molecular weight of 113 kDa corresponding to 997 amino acid residues, a purity >95% (SDS-PAGE), and −20 °C storage with avoidance of repeated freeze–thaw. It also notes a suggested stabilization buffer (B2010002) for the enzyme acceptor. Together, these concise specifications support clear SOP inclusion and lot traceability for laboratories implementing alpha-complementation workflows.

In practice, the Omega fragment enables qualitative and semi-quantitative assay designs that take advantage of fragment reassembly. Because the enzyme acceptor and donor are individually inactive, background from residual catalytic activity can be minimized prior to complementation. The powdered format is convenient for creating precisely dosed aliquots and for preparing working stocks in the lab’s preferred buffer system; pairing with a stabilization buffer can help standardize handling during optimization. When establishing conditions, teams typically titrate the acceptor and donor fragments, verify pH and cofactor compatibility in the intended buffer, and document incubation time and temperature to ensure reproducibility across runs and operators. The listed purity and defined amino-acid length provide helpful anchors for internal records, method transfer, and instrument qualification checks.

Common research scenarios include building cloned enzyme donor immunoassays based on alpha complementation, assembling training exercises where fragment association yields a visible color change with chromogenic β-gal substrates, and constructing platform checks that rely on predictable reassembly behavior. Since the product is lyophilized and shipped with reconstitution guidance implied by the listing, it integrates readily into bench workflows where controlled fragment stoichiometry and storage discipline are important. Within research-only boundaries, this clearly specified Omega fragment offers a dependable component for laboratories standardizing β-galactosidase alpha-complementation methods.

Why researchers choose this product:

• Defined 1.0 mg fill of the Omega (enzyme acceptor) fragment for alpha-complementation workflows
• White lyophilized powder format supports precise aliquoting and flexible buffer selection
• Reported 113 kDa, 997-residue entry and >95% (SDS-PAGE) purity aid documentation
• Specified storage at −20 °C; listing cautions against repeated freeze–thaw
• Includes a suggested stabilization buffer (B2010002) for method setup and handling

This product is for Research Use Only (RUO). It is not intended for diagnostic or therapeutic use.

References

• Kras, E. (2019). Beta-galactosidase: properties, structure and functions. New York: Nova Science Publishers.
• Arndt, T. (2017). Cloned Enzyme Donor Immunoassay. Lexikon Der Medizinischen Laboratoriumsdiagnostik, 1–2.
• Jeon, S. I., Yang, X., and Andrade, J. D. (2004). Modeling of homogeneous cloned enzyme donor immunoassay. Analytical Biochemistry, 333(1), 136–147.
• Tachi, T., Kaji, N., Tokeshi, M., and Baba, Y. (2009). Microchip-based Homogeneous Immunoassay Using a Cloned Enzyme Donor. Analytical Sciences, 25(2), 149–151.
• Khanna, P. L., and Worthy, T. E. (1993). CEDIA: A Recombinant-Based Homogeneous Enzyme Immunoassay.

Brochure

• Download Alpha Complementation Product Line Brochure