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Antennapedia/HS1 chimeric phosphotyrosyl peptide: Conformational properties, binding capability to c‐Fgr SH2 domain and cell permeability
Author(s) -
Ruzza Paolo,
DonellaDeana Arianna,
Calderan Andrea,
Brunati Annamaria,
Massimino Maria Lina,
Elardo Stefano,
Mattiazzo Alessio,
Pinna Lorenzo A.,
Borin Gianfranco
Publication year - 2001
Publication title -
peptide science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/1097-0282(2001)60:4<290::aid-bip9991>3.0.co;2-m
Subject(s) - chemistry , sh2 domain , peptide , phosphorylation , antennapedia , proto oncogene tyrosine protein kinase src , sh3 domain , biochemistry , fusion protein , transmembrane domain , microbiology and biotechnology , biophysics , membrane , recombinant dna , biology , transcription factor , homeobox , gene
With the aim of interfering with the signaling pathways mediated by the SH2 domains of Src‐like tyrosine kinases, we synthesized a tyrosyl‐phospho decapeptide, corresponding to the sequence 392‐401 of HS1 protein, which inhibits the secondary phosphorylation of HS1 protein catalyzed by the Src‐like kinases c‐Fgr or Lyn. This phospho‐peptide was modified to enter cells by coupling to the third helix of Antennapedia homeodomain, which is able to translocate across cell membranes. Here we present CD and fluorescence studies on the conformational behavior in membrane‐mimicking environments and on lipid interactions of Antennapedia fragment and its chimeric phosphorylated and unphosphorylated derivatives. These studies evidenced that electrostatic rather than amphiphilic interactions determine the peptide adsorption on lipids. Experiments performed with recombinant protein containing the SH2 domain of c‐Fgr fused with GST and with isolated erythrocyte membranes demonstrated that the presence of the N‐terminal Antennapedia fragment only slightly affects the binding of the phospho‐HS1 peptide to the SH2 domain. In fact, it has been shown that in isolated erythrocyte membranes, both phospho‐HS1 peptide and its chimeric derivative greatly affect either the SH2‐mediated recruitment of the c‐Fgr to the transmembrane protein band 3 and the following phosphorylation of the protein catalyzed by the Src‐like kinase c‐Fgr. The ability of the chimeric phospho‐peptide to enter cells has been demonstrated by confocal microscopy analysis. © 2001 John Wiley & Sons, Inc. Biopolymers (Pept Sci) 60: 290–306, 2001