Open AccessChemical and physicochemical characterization of the sialic acid‐specific lectin from Cepaea hortensis
Author(s) -
Gerlach Dieter,
Wagner Manfred,
Schlott Bernhard,
Zähringer Ulrich,
Schmidt KarlHerman
Publication year - 2002
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2002.tb11325.x
Subject(s) - sialic acid , lectin , isoelectric point , isoelectric focusing , chemistry , biochemistry , molecular mass , size exclusion chromatography , gel electrophoresis , mannose , chromatography , fetuin , sepharose , glycoprotein , enzyme
A sialic acid‐specific lectin was isolated from the albumin glands of the garden snail Cepaea hortensis by affinity chromatography on fetuin‐Sepharose following gel filtration on Superdex 200. The purified native lectin showed a molecular mass of about 95 kDa by gel filtration and 100 kDa by SDS electrophoresis. It was cleaved by boiling in buffer containing SDS in three serological identical bands corresponding to molecular masses of about 24, 20 and 16 kDa, respectively. From these three fragments, only the 24‐ and the 20‐kDa bands were found to be glycosylated. Only the three sugars mannose, galactose and N ‐acetylglucosamine could be detected in a molar ratio of 3:8.6:2. The oligosaccharide moieties seem to be N ‐ and partially O ‐glycosidic bound. Isoelectric focusing (IEF) of the purified lectin revealed a heterogeneous pattern with bands in the pH range of 4.3–5.0. Isolated bands of different isoelectric points showed in SDS electrophoresis the same three fragments with molecular masses of 24, 20 or 16 kDa. The heterogeneity of the lectin was revealed either by IEF or amino acid sequencing of internal tryptic peptides.