earticle

영어

Factor X(FX) is a vitamin K-dependent plasma protease, two-chain glycoprotein that plays a central role in blood coagulation pathway. Factor X is activated to factor Xa (FXa) in vitro by a factor X activator isolated from Russell's viper venom (RVV). FXa cleaves after the arginine residue in its preferred cleavage site Ile-(Glu or Asp)-Gly-Arg, widely used to remove fusion tags from expressed proteins. In this study, expression was achieved using a full-length FX cDNA. Recombinant human factor X (hFX) was expressed in transgenic rice cell suspension culture under the control of rice amylase 3D promoter (pRAmy3D), which is induced by sugar starvation. hFX mRNA and protein expression in transgenic rice cells were detected by Northern and Western blot analyses. The proteolytic activity of factor Xa, hFX activated with RVV, was characterized by using a EGFP-hTNFa fusion protein as substrate, which contained a factor Xa cleavage site between two moieties. These results demonstrate that the hFX derived from rice cell suspension culture system can be used to cleave the tags from the fusion proteins (This Study was supported by a grant from the Next Generation New Technology Development Project (10030122) of the Ministry of Knowledge Economy).