CHAC2 Human
Description
Product Specs
Product Science Overview
The CHAC2 gene is located on chromosome 2p16.2 . It encodes a protein consisting of 184 amino acids with a molecular mass of approximately 22 kDa . The protein shares 50% amino acid identity with its paralog, CHAC1, and 94% identity with its mouse ortholog . The structure of CHAC2 includes a gamma-glutamylcyclotransferase-like fold, which is essential for its enzymatic activity .
CHAC2 specifically catalyzes the cleavage of glutathione into 5-oxoproline and a Cys-Gly dipeptide . Unlike CHAC1, CHAC2 does not act on other gamma-glutamyl peptides . This enzyme is involved in the continuous, basal turnover of cytosolic glutathione, which is crucial for maintaining cellular redox balance .
In vitro assays with purified recombinant human and mouse CHAC2 have confirmed its substrate specificity for glutathione . Although human CHAC2 exhibits 10- to 20-fold lower catalytic efficiency compared to CHAC1, it plays a significant role in glutathione metabolism .
CHAC2 is ubiquitously expressed in various tissues, with notable expression in the cytoplasm of human embryonic kidney (HEK) cells . Unlike CHAC1, which is upregulated in response to endoplasmic reticulum stress and sulfur starvation, CHAC2 expression remains relatively constant, suggesting its role as a housekeeping enzyme for glutathione degradation .
Phylogenetic analysis has revealed the presence of CHAC2 orthologs in various mammals, zebrafish, fruit flies, plants, yeast, and bacteria . The single E. coli ChaC enzyme exhibits similar catalytic efficiency to human and mouse CHAC2, indicating that E. coli ChaC is functionally orthologous to CHAC2 rather than CHAC1 . This suggests that CHAC2 may be the ancestral enzyme of the ChaC family, responsible for the continuous turnover of glutathione .
