title: Further analogues of plant peptide hormone phytosulfokine-alpha (PSK-alpha) and their biological evaluation.
abstract: Phytosulfokine-alpha (PSK-alpha), a sulfated growth factor of structure H-Tyr(SO3H)-Ile-Tyr(SO3H)-Thr-Gln-OH universally found in both monocotyledons and dicotyledons, strongly promotes proliferation of plant cells in culture. In studies on the structure/activity relationship of PSK-alpha the synthesis was performed of a series of a further 23 analogues modified in position 1, 3 or 4 as well as simultaneously in positions 1 and 3 of the peptide chain. Peptides were synthesized by the solid phase method according to the Fmoc procedure on a Wang-resin. Free peptides were released from the resin by 95% TFA in the presence of EDT. All peptides were tested by competitive binding assay to the carrot membrane using 3H-labelled PSK-alpha according to the test of Matsubayashi et al. Among these peptide analogues, [H-Phe(4-Cl)1]-PSK-alpha (IV), [H-Phe(4-I)1]-PSK-alpha (VII), and [Phe(4-Cl)3]-PSK-alpha (XI) retained 30% PSK-alpha activity. Analogue [Tyr(PO3H2)3]-PSK-alpha (IX) showed 10% of PSK-alpha activity.
authors.affiliation: Faculty of Chemistry, University of Wrocław, 50-383 Wrocław, ul. F. Joliot-Curie 14, Poland.
authors.forename: Agata
authors.initials: A
authors.lastname: Bahyrycz
authors.forename: Yoshikatsu
authors.initials: Y
authors.lastname: Matsubayashi
authors.forename: Mari
authors.initials: M
authors.lastname: Ogawa
authors.forename: Youji
authors.initials: Y
authors.lastname: Sakagami
authors.forename: Danuta
authors.initials: D
authors.lastname: Konopińska
mesh_terms: D001667:Binding, Competitive; D018552:Daucus carota / Q000737:chemistry / Q000166:cytology; D036361:Peptide Hormones; D010937:Plant Growth Regulators / Q000737:chemistry* / Q000494:pharmacology*; D010940:Plant Proteins / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: C100975:PSK-alpha protein, plant; D036361:Peptide Hormones; D010937:Plant Growth Regulators; D010940:Plant Proteins