title: Design, synthesis and properties of synthetic chlorophyll proteins.
abstract: A chemoselective method is described for coupling chlorophyll derivatives with an aldehyde group to synthetic peptides or proteins modified with an aminoxyacetyl group at the epsilon-amino group of a lysine residue. Three template-assembled antiparallel four-helix bundles were synthesized for the ligation of one or two chlorophylls. This was achieved by coupling unprotected peptides to cysteine residues of a cyclic decapeptide by thioether formation. The amphiphilic helices were designed to form a hydrophobic pocket for the chlorophyll derivatives. Chlorophyll derivatives Zn-methyl-pheophorbide b and Zn-methyl-pyropheophorbide d were used. The aldehyde group of these chlorophyll derivatives was ligated to the modified lysine group to form an oxime bond. The peptide-chlorophyll conjugates were characterized by electrospray mass spectrometry, analytical HPLC, and UV/visible spectroscopy. Two four-helix bundle chlorophyll conjugates were further characterized by size-exclusion chromatography, circular dichroism, and resonance Raman spectroscopy.
authors.affiliation: Institut für Biologie II/Biochemie, Albert-Ludwigs-Universität Freiburg, Germany.
authors.forename: H K
authors.initials: HK
authors.lastname: Rau
authors.forename: H
authors.initials: H
authors.lastname: Snigula
authors.forename: A
authors.initials: A
authors.lastname: Struck
authors.forename: B
authors.initials: B
authors.lastname: Robert
authors.forename: H
authors.initials: H
authors.lastname: Scheer
authors.forename: W
authors.initials: W
authors.lastname: Haehnel
mesh_terms: D000595:Amino Acid Sequence; D002734:Chlorophyll / Q000031:analogs & derivatives*; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D015195:Drug Design; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis; D010940:Plant Proteins / Q000138:chemical synthesis* / Q000737:chemistry; D013053:Spectrophotometry; D013059:Spectrum Analysis, Raman
chemical_list: D010455:Peptides; D010940:Plant Proteins; D002734:Chlorophyll