Mutants of β2-glycoprotein I: Their features and potent applications

Publication date: Available online 26 February 2019Source: Best Practice & Research Clinical RheumatologyAuthor(s): Lianhua Shen, Nuriza Ulul Azmi, Xian Wen Tan, Shinsuke Yasuda, Arum Tri Wahyuningsih, Junko Inagaki, Kazuko Kobayashi, Eiji Ando, Takanori Sasaki, Eiji MatsuuraAbstractβ2-Glycoprotein I (β2GPI) is a highly-glycosylated plasma protein composed of five homologous domains which regulates coagulation, fibrinolysis, and/or angiogenesis by interacting to negatively charged hydrophobic molecules and/or with plasminogen and its metabolites. The present study focused on structural and functional characterization of β2GPI's domain I (DI) and V (DV). Through N-terminal amino acid sequencing, a novel plasmin-cleaved site at K287C288 was identified in DV. We further modified the intact DV by altering two amino acids at specific proteolytic cleavage sites to generate three stable DV mutants: DV(PP), (PE), and (AA). Results of both SDS-PAGE and MALDI-TOF-MS showed that all three DV mutants were more stable than the intact DV, and DV(PE) was predominantly resistant to proteolysis. Competitive ELISA assessed affinities of intact β2GPI and those mutants to cardiolipin. In culture system, all DV and DI mutants potently inhibited HUVEC's proliferation by 18–30% as compared to control. Only DI and nicked β2GPI showed significant inhibition in HUVEC's tube formation. Moreover, DV(PE)-coated affinity columns demonstrated its binding property towards anionic lipids and could su...
Source: Best Practice and Research Clinical Rheumatology - Category: Rheumatology Source Type: research