A lectin from the Chinese bird-hunting spider binds sialic acids.
The affinity to sialic acid-containing oligosaccharides of the small-animal lectin SHL-I isolated from the venom of the Chinese bird-hunting spider Selenocosmia huwena is here described for the first time. By a strategic combination of NMR techniques, molecular modeling, and data mining tools it was possible to identify the crucial amino acid residues that are responsible for SHL-I's ability to bind sialic acid residues in a specific way. Furthermore, we are able to discuss the role of the functional groups of sialic acid when bound to SHL-I. Also the impact of Pro31 in its cis- or trans-form on SHL-I's ligand affinity is of special interest, since it answers the question if Trp32 is a crucial amino acid for stabilizing complexes between SHL-I and sialic acid. SHL-I can be considered as a proper model system that provides further insights into the binding mechanisms of small-animal lectins to sialic acid on a sub-molecular level.
Siebert
Hans-Christian
HC
Institut für Biochemie und Endokrinologie, Fachbereich für Veterinärmedizin, Justus-Liebig Universität Giessen, Frankfurter Strasse 100, 35392 Giessen, Germany.
Lu
Shan-Yun
SY
Wechselberger
Rainer
R
Born
Karin
K
Eckert
Thomas
T
Liang
Songping
S
von der Lieth
Claus-Wilhelm
CW
Jiménez-Barbero
Jesús
J
Schauer
Roland
R
Vliegenthart
Johannes F G
JF
Lütteke
Thomas
T
André
Sabine
S
Kaltner
Herbert
H
Gabius
Hans-Joachim
HJ
Kozár
Tibor
T
D000595:Amino Acid Sequence; D000818:Animals; D037102:Lectins / Q000737:chemistry* / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D017433:Protein Structure, Secondary; D012794:Sialic Acids / Q000737:chemistry* / Q000378:metabolism*; D013111:Spider Venoms / Q000378:metabolism; D013112:Spiders / Q000378:metabolism*
D037102:Lectins; D012794:Sialic Acids; D013111:Spider Venoms