Open AccessDesign, synthesis and properties of synthetic chlorophyll proteins
Author(s) -
Rau Harald K.,
Snigula Heike,
Struck Andreas,
Robert Bruno,
Scheer Hugo,
Haehnel Wolfgang
Publication year - 2001
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1327.2001.02231.x
Subject(s) - chemistry , circular dichroism , chlorophyll , aldehyde , stereochemistry , organic chemistry , catalysis
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 ε‐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‐methylpheophorbide 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.