Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.1.5 (urease)
 7,257 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Larvae of the bruchid beetle Caryedes brasiliensis feed exclusively on seeds of the Neotropical legume Dioclea megacarpa, which contains 13 percent L-canavanine by dry weight. L-Canavanine, a nonprotein amino acid analog of L-arginine, exhibits potent insecticidal properties. Most of the seed nitrogen is sequestered in canavanine, and bruchid beetle larvae do not simply excrete this toxic compound. Instead, these larvae possess extraordinarily high urease activity, which facilitates the conversion of canavanine to ammonia through urea. In this way, canavanine is effectively detoxified and a supply of nitrogen for fixation into organic linkage is ensured.
 ...
PMID:Degradation and detoxification of canavanine by a specialized seed predator. 85 40

L-Canavanine competes with L-arginine for incorporation into vitellogenin secreted in vitro by the fat body of the female locust Locusta migratoria migratorioides. Incorporation of L-[guanidinooxy-14C]canavanine into vitellogenin has been established unequivocally by combined arginase and urease hydrolyses of the acid hydrolysate of antibody-precipitated canavanyl vitellogenin. Continued exposure of the fat body to canavanine decreases in vitro protein secretion but the proportion of canavanyl vitellogenin to native vitellogenin increases. Canavanine-mediated inhibition of fat body protein secretion is dependent on both the canavanine concentration and the arginine retention by the fat body. Canavanine replaces about 10% of the arginyl residues of canavanyl vitellogenin. The electrophoretic mobility of canavanyl vitellogenin is greater than that of native vitellogenin but the ability of this aberrant protein to react with vitellogenin antibody is unimpaired.
 ...
PMID:In vitro incorporation of L-canavanine into vitellogenin of the fat body of the migratory locust Locusta migratoria migratorioides. 694 85

Cryptococcus neoformans and Cryptococcus gattii are closely related pathogenic fungi. Cryptococcus neoformans is ecologically widespread and affects primarily immunocompromised patients, while C. gattii is traditionally found in tropical climates and has been reported to cause disease in immunocompetent patients. l-Canavanine glycine bromothymol blue (CGB) agar can be used to differentiate C. neoformans and C. gattii, but there are few reports of its performance in routine clinical practice. Growth of C. gattii on CGB agar produces a blue color, indicating the assimilation of glycine, while C. neoformans fails to cause a color change. Using reference and clinical strains, we evaluated the ability of CGB agar and D2 large ribosomal subunit DNA sequencing (D2 LSU) to differentiate C. neoformans and C. gattii. One hundred two yeast isolates were screened for urease activity, melanin production, and glycine assimilation on CGB agar as well as by D2 sequencing. Seventeen of 17 (100%) C. gattii isolates were CGB positive, and 54 of 54 C. neoformans isolates were CGB negative. Several yeast isolates other than the C. gattii isolates were CGB agar positive, indicating that CGB agar cannot be used alone for identification of C. gattii. D2 correctly identified and differentiated all C. gattii and C. neoformans isolates. This study demonstrates that the use of CGB agar, in conjunction with urea hydrolysis and Niger seed agar, or D2 LSU sequencing can be reliably used in the clinical laboratory to distinguish C. gattii from C. neoformans. We describe how CGB agar and D2 sequencing have been incorporated into the yeast identification algorithm in our laboratory.
 ...
PMID:Identification of Cryptococcus gattii by use of L-canavanine glycine bromothymol blue medium and DNA sequencing. 1979 48