GGH Human

The human recombinant form of GGH is typically expressed in host cells such as HEK293 or E. coli. The recombinant protein often includes a polyhistidine tag (His-tag) to facilitate purification. For example, a recombinant human GGH protein expressed in HEK293 cells consists of 305 amino acids and has a predicted molecular mass of approximately 35.1 kDa . Another variant expressed in E. coli includes a His-tag at the N-terminus and corresponds to amino acids 25-318 of the human GGH .

GGH is a homodimeric protein that catalyzes the cleavage of the gamma-glutamyl chain of folylpoly-gamma-glutamyl substrates. This activity is central to the metabolism of folyl and antifolyl poly-gamma-glutamates . By regulating intracellular folate levels, GGH ensures proper cell proliferation and DNA synthesis. Additionally, GGH plays a role in the bioavailability of dietary pteroylpolyglutamates and the metabolism of antifolates such as methotrexate (MTX), which are used in chemotherapy .

GGH’s role in folate metabolism makes it a significant enzyme in various physiological and pathological processes. For instance, cytoplasmic GGH has been implicated in the development and progression of invasive breast cancer . Understanding the function and regulation of GGH can provide insights into cancer biology and potential therapeutic targets.

Recombinant GGH proteins are typically lyophilized and shipped at ambient temperature. They are stable for up to twelve months when stored at -20°C to -80°C under sterile conditions. It is recommended to aliquot the protein to avoid repeated freeze-thaw cycles .