Xu T, Khanna H, Coward J K
Department of Chemistry, College of Pharmacy, University of Michigan, Ann Arbor 48109, USA.
Bioorg Med Chem. 1998 Oct;6(10):1821-34. doi: 10.1016/s0968-0896(98)00135-7.
The benzophenone photophore was incorporated into protected tripeptides and tetrapeptides as photoactivatable probes to study the multimeric enzyme oligosaccharyltransferase (OST). These peptides contain the -Asn-X-Thr- sequon which is required for OST-catalyzed N-glycosylation. Two tripeptides, Bz-Asn-Bpa-Thr-NH2 (3b) and Bz-Asn-Lys[N epsilon-(4-Bz)Bz]-Thr-NH2 (4b), were found to be good OST substrates. They were competitive inhibitors versus standard peptide substrate [14C]Bz-Asn-Leu-Thr-NH2 and their Ki values were determined to be 41 +/- 6 microM and 21 +/- 6 microM, respectively, using synthetic (GlcNAc)2-PP-dolichol.
二苯甲酮光基团被引入到受保护的三肽和四肽中作为光活化探针，用于研究多聚酶寡糖基转移酶（OST）。这些肽含有OST催化的N-糖基化所需的-Asn-X-Thr-序列。发现两种三肽Bz-Asn-Bpa-Thr-NH2（3b）和Bz-Asn-Lys[Nε-(4-Bz)Bz]-Thr-NH2（4b）是良好的OST底物。它们是标准肽底物[14C]Bz-Asn-Leu-Thr-NH2的竞争性抑制剂，使用合成的(GlcNAc)2-PP-多萜醇测定其Ki值分别为41±6 microM和21±6 microM。
