Synthesis of the Model Peptides of the AGSGAG and minTBP-1
motifs.
To examine the binding mechanism of silk-TBP on the surface of
TiO2 nonoparticles, the model peptides of the AGSGAG and
minTBP-1 motifs, i.e., RKLPDA (minTBP-1) , (AGSGAG)2,
AGSGAGGRKLPDAGGAGSGAG (Silk-TBP), and
AGSG[1-13C]AGGRKLPD[3-13C]AGGAGSGAG
(13C Silk-TBP) were synthesized in a stepwise fashion
on Fmoc-amino acid-PEG-PS resin by a Pioneer Peptide Synthesis System
(PE Biosystems, USA) using Fmoc solid phase method in our laboratory
(Asakura et al., 2005; Asakura & Yao, 2002; Yu Suzuki et al., 2010; Yao
et al., 2004). The purity was more than 95%, as verified by
high-performance liquid chromatography and 13C
solution NMR. The [1-13C]Ala (99.9%13C enrichment) and [3-13C]Ala
(99.9% 13C enrichment) were purchased from Cambridge
Isotopes Laboratories, Andover, MA, USA.