Pyruvate kinase is a key enzyme in the glycolytic pathway that catalyzes the transfer of a phosphoryl group from phosphoenolpyruvate (PEP) to ADP, generating ATP. There are 4 isozymes of pyruvate kinase in mammals: L, R, M1 and M2. M2 pyruvate kinase (M2-PK) is found in early foetal tissues, as well as in most cancer cells. M2-PK occurs in a tetrameric form with a high affinity for PEP and a dimeric form with a low affinity for PEP. The dimeric form has been termed tumour M2-PK due to its predominance in malignant cells. Dimeric tumour M2-PK is formed following direct binding of oncoproteins, resulting in reduced enzyme activity.

Tumour M2-PK has been proposed as a biomarker for breast cancer and colorectal cancer. It can be measured in plasma or stool samples and is reported to be useful for measuring disease activity, sensitivity to chemotherapy and recurrence. The use of Tumour M2-PK screening in faeces has been recommended for large-scale population screening and is claimed to be superior to faecal occult blood tests.

Randox recombinant human M2-PK is suitable for use by researchers from academic and government research institutions, biotechnology, diagnostic and pharmaceutical companies, as well as hospitals and reference laboratories in a wide range of research and development applications. Potential applications include antibody production and characterisation, immunoassay development, and use as a positive control or standard in immunochemical methods, including ELISA and Western blot. Randox recombinant human M2-PK is expressed in E. coli with an amino-terminal hexahistidine tag.