Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: bAggregate structure of hydroxyproline-rich glycoprotein (HRGP) and HRGP assisted dispersion of carbon nanotubes | Nanoscale Res Lett 2006 1 154-159 DOI s11671-006-9006-8 NANO EXPRESS Aggregate structure of hydroxyproline-rich glycoprotein HRGP and HRGP assisted dispersion of carbon nanotubes Ben Wegenhart Li Tan Michael Held Marcia Kieliszewski Liwei Chen Published online 1 August 2006 to the authors 2006 Abstract Hydroxyproline-rich glycoproteins HRGP comprise a super-family of extracellular structural glycoproteins whose precise roles in plant cell wall assembly and functioning remain to be elucidated. However their extended structure and repetitive block co-polymer character of HRGPs may mediate their self-assembly as wall scaffolds by like-with-like alignment of their hydrophobic peptide and hydrophilic glycopeptide modules. Intermolecular crosslinking further stabilizes the scaffold. Thus the design of HRGP-based scaffolds may have practical applications in bionanotechnology and medicine. As a first step we have used single-molecule or single-aggregate atomic force microscopy AFM to visualize the structure of YK20 an amphiphilic HRGP comprised entirely of 20 tandem repeats of Ser-Hyp4-Ser-Hyp-Ser-Hyp4-Tyr-Tyr-Tyr-Lys. YK20 formed tightly aggregated coils at low ionic strength but networks of entangled chains with a porosity of gm at higher ionic strength. As a second step we have begun to design HRGP-carbon nanotube composites. Single-walled carbon nanotubes SWNTs can be considered as seamless cylinders rolled up from graphene sheets. These unique all-carbon structures have extraordinary aromatic and hydrophobic properties and form aggregated bundles due to strong inter-tube van der Waals interactions. Sonicating aggregated SWNT bundles with aqueous YK20 solubilized them presumably by interaction with the repetitive hydrophobic Tyr-rich peptide modules B. Wegenhart L. Tan M. Held M. Kieliszewski L. Chen H Department of Chemistry and Biochemistry Ohio University Athens Ohio 45701 USA e-mail chenl1@ of YK20 with retention of the extended polyproline-II
