Human/Mouse/Rat Cysteine Conjugate beta-Lyase/CCBL1 Antibody

CCBL1 (Cysteine Conjugate beta-Lyase 1; also GTK and KAT-I) is a 90-120 kDa homodimeric member of the Class I Pyridoxyl-phosphate-dependent aminotransferase family of enzymes. It is widely expressed, being found in fibroblasts, renal epithelium, hepatocytes, neurons and astrocytes. CCBL1 has multiple activities, including converting prodrugs into active formulations, generating kynurenic acid from kynurenine, thereby antagonizing NMDA receptors (but not likely presynaptic alpha7 AChRs), and blocking the release of proinflammatory cytokines by microglia via GPCR-35 antagonism. Human CCBL1 is 422 amino acids (aa) in length, and contains one aspartate aminotransferase-like region (aa 31-417). There are three potential splice variants, one that shows a deletion of aa 68-117, a second that shows a deletion of aa 251-422, and a third that contains a 21 aa substitution for aa 230-250. While the 422 aa isoform is considered cytosolic, there is the potential for a 34 aa N-terminal extension that would act as a mitochondrial targeting sequence. Such a sequence is reported for rat and nonhuman primate. Over aa 182-422, human CCBL1 shares 82% aa sequence identity with mouse CCBL1.