The tryptophan fluorescence of Tetracarbidium conophorum agglutinin II and a solution-based assay for the binding of a biantennary glycopeptide.
The plant lectin Tetracarbidium conophorum agglutinin II binds to glycoproteins and glycopeptides in a structurally specific manner [Animashaun et al., (1994) Glycoconjugate J. 11, 299-303]. We have characterized the steady-state and time-resolved fluorescence of the tryptophan residues of this lectin. The fluorescence (lambda[ex] = 295 nm, lambda[em] = 350 nm) decay is complex and can be described by four decay times with the following values: tau1 = 7.4 nsec, alpha1 = 0.22; tau2 = 2.9 nsec, alpha2 = 0.25: tau3 = 1.0 nsec, alpha3 = 0.34, tau4 = 0.2 nsec, alpha4 = 0.18. The addition of a biantennary glycopeptide (carbohydrate sequence [see text]) to the lectin results in a quench and an 8 nm blue shift of the emission spectrum. The effect is saturable, and is described by an association constant of 1.8 x 10(5) M(-1). The tryptophan fluorescence of Tetracarbidium conophorum agglutinin II may therefore be utilized to characterize thermodynamically the binding interactions between this lectin and complex glycoprotein.
Brown
M P
MP
Department of Biology, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
Toptygin
D
D
Lee
K B
KB
Animashaun
T
T
Hughes
R C
RC
Lee
Y C
YC
Brand
L
L
D002240:Carbohydrate Sequence; D006020:Glycopeptides / Q000378:metabolism*; D037102:Lectins / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D037121:Plant Lectins; D010945:Plants, Edible / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
D006020:Glycopeptides; D037102:Lectins; D037121:Plant Lectins; C111882:tetracarbidium conophorum agglutinin II