Application of peptide probe for evaluating affinity properties of proteins using quartz crystal microbalance.
This study proved a possibility of a peptide probe for evaluating affinity properties of proteins. We have designed and synthesized three different peptide probes, H-Ala3-(Gly-Pro5)3-Gly-OH (peptide A), H-Ala3-(Gly-Pro5)-Gly-OH (peptide B) and H-Ala3-Gly-OH (peptide C) for testing their affinities to profilin. Each peptide probe was immobilized on a quartz crystal microbalance (QCM) sensor. The QCM sensor with the peptide A showed a 93 Hz decrease of resonant frequency which indicated profilin bound to the QCM sensor in a single layer. In a successive reaction with actin, the QCM analysis resulted in a 123 Hz decrease of resonant frequency which showed actin bound to the QCM sensor. A fluorescence microscope image of the sensor surface exhibited clear fluorescence after binding a rhodamine labeled actin on the sensor surface. These results supported stepwise reactions of profilin binding to the peptide A and actin binding to profilin. In the three peptide probes, the peptide A showed the highest affinity to profilin, i.e., sequence dependent affinity was confirmed.
Okada
Tomoko
T
School of Bionics, Tokyo University of Technology, Katakura, Hachioji, Tokyo 192-0982, Japan.
Yamamoto
Yuji
Y
Miyachi
Hirotaka
H
Karube
Isao
I
Muramatsu
Hiroshi
H
D000199:Actins / Q000378:metabolism; D000345:Affinity Labels; D015336:Molecular Probe Techniques; D015335:Molecular Probes; D010455:Peptides; D051304:Profilins / Q000378:metabolism; D011485:Protein Binding / Q000502:physiology; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*
D000199:Actins; D000345:Affinity Labels; D015335:Molecular Probes; D010455:Peptides; D051304:Profilins; D011506:Proteins