کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5514603 | 1541685 | 2017 | 8 صفحه PDF | دانلود رایگان |
- The first CTPS1-selective inhibitory peptide CTpep-3 was discovered.
- CTpep-3 showed KD value of 210Â nM in SPR analysis and IC50 value of 110Â nM in enzyme assay.
- Enzyme assay and HDX-MS analysis indicated CTpep-3 binds to ALase domain of CTPS1.
Cytidine triphosphate synthase 1 (CTPS1) is an enzyme expressed in activated lymphocytes that catalyzes the conversion of uridine triphosphate (UTP) to cytidine triphosphate (CTP) with ATP-dependent amination, using either L-glutamine or ammonia as the nitrogen source. Since CTP plays an important role in DNA/RNA synthesis, phospholipid synthesis, and protein sialyation, CTPS1-inhibition is expected to control lymphocyte proliferation and size expansion in inflammatory diseases. In contrast, CTPS2, an isozyme of CTPS1 possessing 74% amino acid sequence homology, is expressed in normal lymphocytes. Thus, CTPS1-selective inhibition is important to avoid undesirable side effects. Here, we report the discovery of CTpep-3: Ac-FRLGLLKAFRRLF-OH from random peptide libraries displayed on T7 phage, which exhibited CTPS1-selective binding with a KD value of 210Â nM in SPR analysis and CTPS1-selective inhibition with an IC50 value of 110Â nM in the enzyme assay. Furthermore, two fundamentally different approaches, enzyme inhibition assay and HDX-MS, provided the same conclusion that CTpep-3 acts by binding to the amidoligase (ALase) domain on CTPS1. To our knowledge, CTpep-3 is the first CTPS1-selective inhibitor.
Journal: Peptides - Volume 94, August 2017, Pages 56-63