Arabinogalactan-proteins from cell suspension cultures of Araucaria angustifolia.
Arabinogalactan-proteins (AGPs), found in the culture medium of suspension cells of Araucaria angustifolia grown in plant growth regulator-free and plant growth regulator-containing BM media, BM0 and BM2, respectively, were evaluated quantitatively and qualitatively. The concentrated extracellular fractions (CEFs), obtained from suspension cell cultures grown for 20 days in BM0 and BM2 media yielded two fractions, CEF-0 and CEF-2, respectively. CEF-0 and CEF-2 was submitted to selective precipitation using the beta-glucosyl Yariv reagent (beta-GlcY) to isolate AGPs for structural characterization; this yielded fractions designated CEF-0YPF and CEF-2YPF, respectively. The monosaccharide composition analysis established that samples were composed of Rha, Ara, Gal and uronic acid in a molar ratio 3:37:55:5 (CEF-0YPF) and 1:37:58:4 (CEF-2YPF), although trace amounts (<0.5 mol%) of Xyl were also found. Methylation analysis of CEF-YPF fractions showed similar results for both CEF-0YPF and CEF-2YPF, with non-reducing terminal units of Araf, Arap, Galp, Rhap and Xylp, as well as 3-O-substituted and 5-O-substituted Araf units and 3-O-substituted, 6-O-substituted and 3,6-di-O-substituted Galp units. The amino acid composition analysis established Ser, Ala, and Hyp as major amino acids in both samples. In conclusion, this investigation has shown that CEF-0YPF and CEF-2YPF contain macromolecules having typical AGP characteristics, including a Hyp/Ala/Ser-rich protein moiety, a (1-->3) and/or (1-->6) linked beta-d-galactopyranosyl main chain substituted by Gal, Ara, Rha and Xyl residues, and binding affinity for beta-GlcY and monoclonal anti-AGP antibodies.
Maurer
Juliana Bello Baron
JB
Department of Biochemistry and Molecular Biology-SCB, Parana Federal University, P.O. Box 19046, 81531-990 Curitiba, PR, Brazil. jumaurer@ufpr.br
Bacic
Antony
A
Pereira-Netto
Adaucto Bellarmino
AB
Donatti
Lucélia
L
Zawadzki-Baggio
Selma Faria
SF
Pettolino
Filomena Angela
FA
D000596:Amino Acids / Q000032:analysis*; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D005685:Galactans / Q000737:chemistry / Q000302:isolation & purification; D009005:Monosaccharides / Q000032:analysis; D009088:Mucoproteins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010940:Plant Proteins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification; D011134:Polysaccharides / Q000032:analysis; D064028:Tracheophyta / Q000737:chemistry* / Q000166:cytology / Q000254:growth & development
D000596:Amino Acids; D005685:Galactans; D009005:Monosaccharides; D009088:Mucoproteins; D010940:Plant Proteins; D011134:Polysaccharides; C006619:arabinogalactan proteins