We investigated self-assembly such as hexamerization and two-dimensional crystallization of immunoglobulin G (IgG) molecules on mica by atomic force microscopy. We also estimated the association rate constant of the self-assembled IgG antibodies.
The specific recognization between galactose group and Ricinus Communis Agglutinin (RCA) was investigated by microcantilever. The gold side of the microcantilever was covalently bound with N-galactose, RCA and asialofetuin (ASF) via mixed self assembly monolayer of 11-mercaptoundecanoic acid and 6-mercaptohexanol, respectively. After adding RCA into the flowing cell, the deflection could be observed on the N-galactose or ASF modified microcantilever. Meanwhile, the deflection could also be observed after ASF bound to the RCA modified microcantilever. In order to prove that the deflection is caused by the specific interaction between the galactose group and RCA, bovine serum albumin (BSA) was introduced into the flowing cell as control experiment and no obvious deflection was observed. The specific interaction was also confirmed by the evidence that the bound protein layer can be mechanically removed with atomic force microscopy nanolithography technology.
Growth hillocks on the {100} faces of L-arginine phosphate monohydrate (LAP) single crystals grown at 25°C and at a supersaturation of 0.32 have been discussed. The typical dislocation growth hillocks are lopsided and elongate along the b direction. The dislocation sources are probably caused by the extra stress field which is introduced by the hollow cavities distributing on the steps and hillocks generated by the two-dimensional nucleus. The elongated shape is due to the characteristic structure of the LAP crystal. Apart from that, the formation of the lopsided growth hillocks is explained by the liquid flow theory.
Immunoactivity of self-assembled antibodies investigated by atomic force microscopy