An ss-DNA gold chip was prepared based on self-assembly of the thiol-derivatized oligonucleotide, and used for the determination of single-stranded binding protein （SSB） by surface plasmon resonance microscopy （SPR...An ss-DNA gold chip was prepared based on self-assembly of the thiol-derivatized oligonucleotide, and used for the determination of single-stranded binding protein （SSB） by surface plasmon resonance microscopy （SPR）. The experiment results showed that SSB binds ss-DNA with high specificity, and relative signal of SPR response is proportional to the concentration of SSB in the range of 0.1-100 ng/mL with a detection limit （S/N = 3） of 0.07 ng/mL.展开更多
Rheumatoid factors(RFs) are the characteristic autoantibodies of rheumatoid arthritis. Recent researches in our laboratory showed that the immobilized single-stranded DNA(ss-DNA) immunoadsorbent can selectively remove...Rheumatoid factors(RFs) are the characteristic autoantibodies of rheumatoid arthritis. Recent researches in our laboratory showed that the immobilized single-stranded DNA(ss-DNA) immunoadsorbent can selectively remove RFs from the serum of patients. In the present paper are studied the modification of argininine, tryptophan, lysine residues and carboxyl terminus of IgGRF, which was separated from patients′ serum, with 1,2-cyclohexanedione(CHD), N-bromosuccinimide(NBS), pyridoxal 5′-phosphate(PP) and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide(EDC) respectively, and their effects on the adsorption capacity of the immobilized ss-DNA immunoadsorbent for IgGRF. After the specific modification, the corresponding adsorption capacities of the adsorbents were changed from 48%, 46%, 44% and 54% to 84%, 14%, 21% and 81%, respectively. These results indicate that the electrostatic or ionic-bonding is essential for the interaction between ss-DNA and IgGRF.展开更多
Using a molecular theory, we investigate the temperature-dependent self-assembly of single-stranded DNA（ss DNA）tethered to a charged nanoparticle surface. Here the size, conformations, and charge properties of ss DN...Using a molecular theory, we investigate the temperature-dependent self-assembly of single-stranded DNA（ss DNA）tethered to a charged nanoparticle surface. Here the size, conformations, and charge properties of ss DNA are taken into account. The main results are as follows： i） when the temperature is lower than the critical switching temperature, the ss DNA will collapse due to the existence of electrostatic interaction between ss DNA and charged nanoparticle surface; ii）for the short ss DNA chains with the number of bases less than 10, the switching of ss DNA cannot happen, and the critical temperature does not exist; iii） when the temperature increases, the electrostatic attractive interaction between ss DNA and charged nanoparticle surface becomes weak dramatically, and ss DNA chains will stretch if the electrostatic attractive interaction is insufficient to overcome the elastic energy of ss DNA and the electrostatic repulsion energy. These findings accord well with the experimental observations. It is predicted that the switching of ss DNA will not happen if the grafting densities are too high.展开更多
基金the Science Foundation of the National Education Ministry （No, 206096） the Education Department of Hubei Province （No. Z200522002）.
文摘An ss-DNA gold chip was prepared based on self-assembly of the thiol-derivatized oligonucleotide, and used for the determination of single-stranded binding protein （SSB） by surface plasmon resonance microscopy （SPR）. The experiment results showed that SSB binds ss-DNA with high specificity, and relative signal of SPR response is proportional to the concentration of SSB in the range of 0.1-100 ng/mL with a detection limit （S/N = 3） of 0.07 ng/mL.
基金Key Projectof National Basic Science and Developm ent(No.G19990 6 4 70 7) and Tianjin- Nankai U niversi-ty Co- Construction Foundation and China- UK Collaboration Project
文摘Rheumatoid factors(RFs) are the characteristic autoantibodies of rheumatoid arthritis. Recent researches in our laboratory showed that the immobilized single-stranded DNA(ss-DNA) immunoadsorbent can selectively remove RFs from the serum of patients. In the present paper are studied the modification of argininine, tryptophan, lysine residues and carboxyl terminus of IgGRF, which was separated from patients′ serum, with 1,2-cyclohexanedione(CHD), N-bromosuccinimide(NBS), pyridoxal 5′-phosphate(PP) and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide(EDC) respectively, and their effects on the adsorption capacity of the immobilized ss-DNA immunoadsorbent for IgGRF. After the specific modification, the corresponding adsorption capacities of the adsorbents were changed from 48%, 46%, 44% and 54% to 84%, 14%, 21% and 81%, respectively. These results indicate that the electrostatic or ionic-bonding is essential for the interaction between ss-DNA and IgGRF.
基金Project supported by the Joint Funds of Xinjiang Natural Science Foundation,China(Grant No.2015211C298)
文摘Using a molecular theory, we investigate the temperature-dependent self-assembly of single-stranded DNA（ss DNA）tethered to a charged nanoparticle surface. Here the size, conformations, and charge properties of ss DNA are taken into account. The main results are as follows： i） when the temperature is lower than the critical switching temperature, the ss DNA will collapse due to the existence of electrostatic interaction between ss DNA and charged nanoparticle surface; ii）for the short ss DNA chains with the number of bases less than 10, the switching of ss DNA cannot happen, and the critical temperature does not exist; iii） when the temperature increases, the electrostatic attractive interaction between ss DNA and charged nanoparticle surface becomes weak dramatically, and ss DNA chains will stretch if the electrostatic attractive interaction is insufficient to overcome the elastic energy of ss DNA and the electrostatic repulsion energy. These findings accord well with the experimental observations. It is predicted that the switching of ss DNA will not happen if the grafting densities are too high.
