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Identification Of Two Distinct Glutaminyl Cyclase Isoforms In Drosophila Melanogaster, Amanda Thigpen Parker

Dissertations

Sequence analyses revealed two putative glutaminyl cyclase genes in Drosophila melanogaster with greater than 60% amino acid sequence identity to previously identified glutaminyl cyclase in humans. Expression, purification, and characterization of both putative proteins revealed two enzymatically active glutaminyl cyclase enzymes. Comparison of the Drosophila melanogaster glutaminyl cyclase enzymes to the published human glutaminyl cyclase revealed the enzymes were very similar. The Km values obtained were identical to those of human glutaminyl cyclase for three different substrates tested. However, the Drosophila glutaminyl cyclases demonstrated lower turnover numbers. Both Drosophila glutaminyl cyclase isoforms were inhibited by imidazole, imidazole derivatives, and metal …