Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
602889 | Colloids and Surfaces B: Biointerfaces | 2007 | 7 Pages |
Abstract
Kinetic studies on the interactions between self-assembled monolayers of mannosylerythritol lipids (MELs), which are glycolipid biosurfactants abundantly produced by microorganisms, and various classes of immunoglobulins including human IgG, IgA, and IgM were performed using surface plasmon resonance (SPR). The effect of the MEL structure on the binding behavior of HIgG was examined. Assembled monolayers of MEL-A having two acetyl groups on the headgroup gave a high affinity (Kd = 1.7 Ã 10â6 M) toward HIgG, while those of MEL-B or MEL-C having only one acetyl group at C-6â² or C-4â² position gave little affinity. Our kinetic analysis revealed that the binding manner of HIgG, HIgA (Kd = 2.4 Ã 10â7 M), and HIgM (Kd = 2.2 Ã 10â7 M) to the assembled monolayers of MEL-A is not the monovalent mode but the bivalent mode, and both the first and second rate association constants (ka1, ka2) increase with an increase in the number of antibody binding sites, while those for dissociation (kd1, kd2) changed little. Moreover, we succeeded in directly observing great amounts of HIgG, HIgA, and HIgM bound to MEL-A monolayers using atomic force microscopy (AFM). Finally, we found that MEL-A assembled monolayer binds toward various IgG derived from mouse, pig, rabbit, horse, goat, rat, and bovine as well as human IgG (HIgG), and the only exception was sheep IgG. These results clearly demonstrate that MEL-A assembled monolayers would be useful as noble affinity ligand system for various immunoglobulins.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Colloid and Surface Chemistry
Authors
Seya Ito, Tomohiro Imura, Tokuma Fukuoka, Tomotake Morita, Hideki Sakai, Masahiko Abe, Dai Kitamoto,