Author:
Tit-oon Phanthakarn,Wonglangka Arisa,Boonkanta Klaichan,Ruchirawat Mathuros,Fuangthong Mayuree,Sasisekharan Ram,Khongmanee Amnart
Abstract
AbstractProgrammed cell death protein 1 (PD-1) is a key receptor in the immune checkpoint pathway and has emerged to be a promising target for cancer therapy. PD-1 consists of an intracellular domain followed by a transmembrane domain that is connected to the extracellular domain by the stalk region. Although the PD-1 structure has been studied for more than two decades, the posttranslational modification of this protein has been incompletely characterized. In this study, we identified the previously undescribed modification sites of O-linked glycan on the stalk region of PD-1 protein using O-protease digestion coupling with intact mass analysis. The result indicates that T153, S157, S159, and T168 are modified by sialylated mucin-type O-glycan with core 1- and core 2-based structures. This study provides both information on potential novel modification sites on the PD-1 protein and an attractive method for identifying O-linked glycosylation using a specific enzyme and intact mass analysis.
Funder
Center of Excellence on Environmental Health and Toxicology (EHT), OPS, Ministry of Higher Education, Science, Research and Innovation
Thailand Science Research and Innovation
Publisher
Springer Science and Business Media LLC