Disease relevance of CCBL1

• Overexpression of cysteine S-conjugate beta-lyase activity had no effect on the toxicity of either drug [1].
• The current study analysed kynurenine aminotransferase I (KAT I) activity and kynurenic acid (KYNA) concentrations in human senile cataractous lenses and in experimentally induced cataracts in diabetic rats treated with streptozotocin (STZ) [2].

High impact information on CCBL1

• Previous mechanistic studies from our laboratory (Spence, R. A., Kati, W. M., Anderson, K. S., and Johnson, K. A. (1995) Science 267, 988-993) have shown that the natural deoxynucleoside triphosphate and the NNRTI can simultaneously bind to their respective sites [3].
• The purified enzyme is not recognized by polyclonal rabbit antibodies to cytosolic rat kidney glutamine transaminase K (another cysteine-S-conjugate beta-lyase of rat kidney) and has no obvious similarities to other pyridoxal 5'-phosphate-containing enzymes [4].
• Isolation from rat kidney of a cytosolic high molecular weight cysteine-S-conjugate beta-lyase with activity toward leukotriene E4 [4].
• For each species, the activity of glutamine transaminase K is higher in the astrocytes than in the neurons [5].
• Glutamine transaminase K may be involved in glutamine cycling in astrocytes [5].

Chemical compound and disease context of CCBL1

• These data demonstrate that cisplatin kills quiescent renal cells by a mechanism that is distinct from the mechanism by which it kills dividing cells and that the renal toxicity of cisplatin is dependent on cysteine S-conjugate beta-lyase activity [1].
• In contrast, carboplatin, a non-nephrotoxic derivative of cisplatin, was 20-fold less toxic than cisplatin in confluent cells, and its toxicity was not altered by overexpression of cysteine S-conjugate beta-lyase [1].

Biological context of CCBL1

• Cysteine-S-conjugate beta-lyase activity and pyridoxal phosphate binding site of onion alliin lyase [6].

Anatomical context of CCBL1

• In the chick embryo, cerebral glutamine transaminase K activity is low between embryonic days 5 and 17, but by day 23 (day of hatching) activity rises dramatically (> 15-fold) [5].
• In this study, LLC-PK1 cells were transfected with human glutamine transaminase K, which catalyzes the beta-elimination reaction [1].
• LLC-PK1 cells, a proximal tubule cell line with low cysteine S-conjugate beta-lyase activity, are used to study cisplatin nephrotoxicity [1].
• Effect of 6-hydroxydopamine treatment on kynurenine aminotransferase-I (KAT-I) immunoreactivity of neurons and glial cells in the rat substantia nigra [7].

Associations of CCBL1 with chemical compounds

• Glutamine transaminase K appears to be a major cysteine S-conjugate beta-lyase of the brain and may play a role in the neurotoxicity associated with exposure to dichloroacetylene and perhaps to other toxins [5].
• Role of cysteine S-conjugate beta-lyase in the metabolism of cisplatin [1].
• We have shown with immunohistochemical techniques that kynurenine aminotransferase-I (KAT-I), the enzyme taking part in the formation of kynurenic acid (KYNA)-the only known endogenous selective NMDA receptor antagonist and a potent neuroprotective agent-is also expressed in the rat SNPC [7].
• The procedure involves the coupling of bacterial phenylalanine dehydrogenase with rat kidney cytosolic glutamine transaminase K. The latter enzyme possesses high affinity for phenylpyruvate [8].
• CONCLUSION: The significant correlation between KYNA and Gln concentrations in vivo may support the previous finding that kynurenine aminotransferase I (KAT I), responsible for the biosynthesis of KYNA, was identical to Gln transaminase K (GTK), which catalyses the transamination of Gln to 2-oxoglutamic acid [9].

Other interactions of CCBL1

• In liver, kynurenine 3-monooxygenase and kynurenine-oxoglutarate transaminase activities did not show any significant difference among the three groups of rabbits [10].

References