Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.4.1.4 (glutamate dehydrogenase)
 4,358 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Current assays for the glutaminyl-peptide cyclizing enzyme, glutaminyl cyclase, have several shortcomings. In this report a rapid spectrophotometric assay for cyclization of glutaminyl-peptides to pyroglutamyl-peptides by glutaminyl cyclase is described which overcomes many of these shortcomings. This coupled assay utilizes glutamate dehydrogenase, alpha-ketoglutarate and NADH to measure the ammonia released during cyclization of the dipeptide substrate Gln-Gln. Glutaminyl cyclase from bovine pituitary, partially purified by ion exchange chromatography, exhibits a Km for this substrate of 0.6 mM and a Vmax of 9.6 nmol/min/mg protein. These values are comparable to ones previously reported using other glutaminyl-peptide substrates and either radioimmunoassay or high-performance liquid chromatography to measure glutaminyl cyclase activity.
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PMID:A spectrophotometric assay for glutaminyl-peptide cyclizing enzymes. 281 31