A quartz crystal microbalance method for rapid detection and differentiation of shiga toxins by applying a monoalkyl globobioside as the toxin ligand.
A simple globobiosyl (Gb2) ceramide mimic carrying a monoalkyl chain (C18) was applied for a monolayer Langmuir-Blodgett (L-B) technique to detect Shiga toxins (Stxs) by a quartz crystal microbalance (QCM) method. The artificial glycolipid, synthesized from penta-O-acetyl-D-galactopyranose via a conventional glycosidation pathway, was developed at the air-water surface for the formation of the monolayer film. Then, the film was transferred onto a QCM cell surface modified with alkanethiols. Upon the addition of each of Stx-1 and Stx-2, the decrease of frequency reached saturation within 45 min at a few nanogram order per quartz cell. Binding constants (Ka) estimated for each of Stx-1 and Stx-2 showed little difference between the two toxins. On the other hand, in the presence of an artificial acrylamido Gb2 copolymer as a competitive inhibitor, the two toxins showed a large difference in the binding behavior to the L-B monolayer.
Uzawa
Hirotaka
H
Nanoarchitectonics Research Center (NARC), National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba 305-8565, Japan. h.uzawa@aist.go.jp
Kamiya
Shoko
S
Minoura
Norihiko
N
Dohi
Hirofumi
H
Nishida
Yoshihiro
Y
Taguchi
Kazuhiro
K
Yokoyama
Shin-Ichiro
S
Mori
Hiroshi
H
Shimizu
Toshimi
T
Kobayashi
Kazukiyo
K
D001667:Binding, Competitive; D019411:Clinical Laboratory Techniques / Q000295:instrumentation; D004927:Escherichia coli Infections / Q000175:diagnosis; D019453:Escherichia coli O157 / Q000737:chemistry; D005915:Globosides / Q000138:chemical synthesis; D006801:Humans; D008024:Ligands; D018716:Molecular Mimicry; D011485:Protein Binding; D011791:Quartz; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; D022603:Shiga Toxins / Q000032:analysis*; D013499:Surface Properties; D014894:Weights and Measures
D005915:Globosides; D008024:Ligands; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; D022603:Shiga Toxins; D011791:Quartz