1H NMR study of the interaction of N,N',N"-triacetyl chitotriose with Ac-AMP2, a sugar binding antimicrobial protein isolated from Amaranthus caudatus.
The interaction between Ac-AMP2, a lectin-like small protein with antimicrobial and antifungal activity isolated from Amaranthus caudatus, and N,N',N"-triacetyl chitotriose was studied using 1H NMR spectroscopy. Changes in chemical shift and line width upon increasing concentration of N,N',N"-triacetyl chitotriose to Ac-AMP2 solutions at pH 6.9 and 2.4 were used to determine the interaction site and the association constant Ka. The most pronounced shifts occur mainly in the C-terminal half of the sequence. They involve the aromatic residues Phe18, Tyr20 and Tyr27 together with their surrounding residues, as well as the N-terminal Val-Gly-Glu segment. Several NOEs between Ac-AMP2 and the N,N',N"-triacetyl chitotriose resonances are reported.
Verheyden
P
P
High Resolution NMR Centre, Vrije Universiteit Brussel, Belgium.
Pletinckx
J
J
Maes
D
D
Pepermans
H A
HA
Wyns
L
L
Willem
R
R
Martins
J C
JC
D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000737:chemistry; D001665:Binding Sites; D002240:Carbohydrate Sequence; D006859:Hydrogen; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D012639:Seeds / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D014312:Trisaccharides / Q000737:chemistry* / Q000378:metabolism*
D000935:Antifungal Agents; D010940:Plant Proteins; D014312:Trisaccharides; C074242:AMP2 protein, Amaranthus caudatus; C019117:N,N',N''-triacetylchitotriose; C041161:chitotriose; D006859:Hydrogen