The amino-acid sequence of the abalone (Haliotis laevigata) nacre protein perlucin. Detection of a functional C-type lectin domain with galactose/mannose specificity.
Perlucin isolated from abalone nacre consists of 155 amino acids including a glycosylated asparagine. The sequence of the first 130 amino acids shows a high similarity to the C-type carbohydrate-recognition domains of asialoglycoprotein receptors and other members of the group of C-type lectins but also a weaker similarity to related proteins without carbohydrate-binding activity. This C-type module is followed by a short C-terminal domain containing two almost identical sequence repeats with a length of 10 amino acids. Solid phase assays show a divalent metal ion-dependent binding of perlucin to (neo)glycoproteins containing D-galactose or D-mannose/D-glucose indicating that perlucin is a functional C-type lectin with broad carbohydrate-binding specificity. Our results also indicate that it may be difficult to predict carbohydrate-binding specificity and the occurrence of alternative binding configurations by amino-acid sequence comparisons and homology modeling.
Max-Planck-Institut für Biochemie, Martinsried, Germany. mann@biochem.mpg.de
K
K
Mann
I M
IM
Weiss
S
S
André
H J
HJ
Gabius
M
M
Fritz
D000595:Amino Acid Sequence; D000818:Animals; D002122:Calcium Chloride / Q000494:pharmacology; D005690:Galactose; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D037102:Lectins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D008358:Mannose; D008969:Molecular Sequence Data; D008974:Mollusca / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012965:Sodium Chloride / Q000494:pharmacology
D006023:Glycoproteins; D037102:Lectins; D010446:Peptide Fragments; C403488:perlucin, Haliotis laevigata; D012965:Sodium Chloride; D002122:Calcium Chloride; D008358:Mannose; D005690:Galactose