Naslov
Synthesis and characterization of the Nω , Nω -dimethylarginine rich C-terminal region of human nucleolin

Autori
Zahariev, Sotir ; Guarnaccia, Corrado ; Zanuttin, Francesco ; Pintar, Alessandro ; Maravić, Gordana ; Pongor, Sandor

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, ostalo

Izvornik
Proceedings of the 27th European Peptide Symposium / Benedetti, Ettore ; Pedone, Carlo - Napulj : Edizioni Ziino, 2002, 336-337

ISBN
88-900948-1-8

Skup
27th European Peptide Symposium

Mjesto i datum
Sorrento, Italija, 2002

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
nukleolin; sinteza peptida; dimetilacija; arginin
(nucleolin; peptide synthesis; dimethylation; arginine)

Sažetak
Both versions of C-terminal region of human nucleolin ChNu (646-706), containing Arg (I), respectively Nω , Nω -dimethylarginine (II), from the family of RGG-rich proteins, were successfully synthesized by an automated Fmoc methodology for SPPS using dimethoxybenzyl as a reversible amide bond protecting group. The cleavage/deprotection conditions were optimized and ChNu's were purified to homogeneity >95% by a combination of IE- and RP-HPLC. The purity/identity of peptides were confirmed by ESI-MS, AAA, SDS-PAGE, RP HPLC in two different systems and by IE HPLC. Arg-dimethylation increases hydrophobicity, as determined by RP-HPLC, and decreases basicity (IE-HPLC). In double filter binding assays (I) and (II) show very similar binding potency to single-stranded DNA (ssDNA) with values comparable to that of recombinant fusion ChNu (Kd ~ 2X10-7 M). The nucleic acid binding affinity is substantially increased in comparison to our published result on short peptides and correlates with the higher number of RGG, respectively aDma-GG-repeats. In a ssDNA-agarose affinity chromatography experiment Arg-dimethylation decreased the electrostatic interaction with ssDNA. Both (I) and (II) show very similar binding potency to G4 DNA and do not exhibit helicase activity in a M13 phage assay. (I) is efficiently, but not exhaustively methylated in vitro by recombinant protein arginine N-methyltransferase type I. 1H NMR spectra of (I) and (II) are characterized by the lack of dispersion for NH and Hα chemical shifts suggesting the absence of globular structure.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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