Article info Vol. 7  No. 4   pp.  90 ~ 93
Title Preliminary crystallographic analysis of the Fab fragment of camrelizumab, a therapeutic antibody against PD-1
Authors Heejin Lim, Hyun Tae Lee, Sang Hyung Lee, Yujin Kim and Yong-Seok Heo*
Institutions Department of Chemistry, Konkuk University, Seoul 05029, Republic of Korea *Correspondence: ysheo@konkuk.ac.kr
Abstract Programmed death 1 (PD-1) is a coinhibitory receptor on the T-cell surface and its primary biological function is to maintain peripheral tolerance by suppressing T-cell activation through the interaction with its ligands PD-L1 and PD-L2. However, cancer cells can evade immunological recognition and destruction by activating coinhibitory pathways through the molecular interactions of PD-1. Recently, the FDA-approved antibodies targeting PD-1 have brought about a significant breakthrough in the treatment of a wide range of cancers, as they can induce durable therapeutic responses. Here, the Fab fragment of camrelizumab, a therapeutic antibody against PD-1, was overexpressed in the periplasmic region of Escherichia coli and purified, and crystallized. The crystal diffracted to 3.25 Å resolution and belonged to the space group C2, with unit cell parameters a = 274.24, b = 77.90, c = 97.16 Å, and β = 101.93˚. An asymmetric unit of the crystal contains four molecules of the Fab fragment of camrelizumab with a VM of 2.51 Å3 Da-1 and a solvent content of 50.96%.