Asunto(s)
Fibroma Osificante , Osteocondroma , Neoplasias de los Tejidos Blandos , Humanos , Fibroma Osificante/complicaciones , Fibroma Osificante/diagnóstico por imagen , Fibroma Osificante/cirugía , Radio (Anatomía)/diagnóstico por imagen , Extremidad Superior , Osteocondroma/complicaciones , Osteocondroma/diagnóstico por imagen , Osteocondroma/cirugíaRESUMEN
Protein tyrosine sulfation (PTS) is a key modulator of extracellular protein-protein interaction (PPI), which regulates principal biological processes. For example, the capsid protein VP1 of enterovirus 71 (EV71) specifically interacts with sulfated P-selectin glycoprotein ligand-1 (PSGL-1) to facilitate virus invasion. Currently available methods cannot be used to directly observe PTS-induced PPI. In this study, atomic force microscopy was used to measure the interaction between sulfated or mutated PSGL-1 and VP1. We found that the binding strength increased by 6.7-fold following PTS treatment on PSGL-1 with a specific antisulfotyrosine antibody. Similar results were obtained when the antisulfotyrosine antibody was replaced with the VP1 protein of EV71; however, the interaction forces of VP1 were only approximately one-third of those of the antisulfotyrosine antibody. We also found that PTS on the tyrosine-51 residue of glutathione S-transferases fusion-PSGL-1 was mainly responsible for the PTS-induced PPI. Our results contribute to the fundamental understanding of PPI regulated through PTS.
Asunto(s)
Proteínas de la Cápside/fisiología , Glicoproteínas de Membrana/fisiología , Microscopía de Fuerza Atómica , Proteínas Virales/fisiología , Glutatión Transferasa/metabolismo , Interacciones Huésped-Patógeno , Humanos , Glicoproteínas de Membrana/genética , Mutación , Tirosina/metabolismo , Acoplamiento ViralRESUMEN
Triacylglycerol lipase from Pseudomonas cepacia and Fe(3)O(4) magnetic nanoparticles were encapsulated simultaneously within biomimetic silica through the catalysis of polyallylamine. The encapsulation efficiency reached 96% with an activity recovery of 51%. After 5 h at 37°C, the activities of the free and encapsulated lipases decreased by 77 and 16%, respectively. Addition of 10 and 15 mol% trimethylmethoxysilane to tetramethoxysilane during encapsulation doubled the lipase activity while inclusion of 50 and 60 mol% γ-(methacryloxypropyl)-trimethoxysilane tripled the activity. Thus, such encapsulation not only stabilized P. cepacia lipase but also could enhance the activity by varying silane additives.
