Kimura Y, Yamaguchi K, Funatsu G
Department of Bioresources Chemistry, Okayama University, Japan.
Biosci Biotechnol Biochem. 1996 Mar;60(3):537-40. doi: 10.1271/bbb.60.537.
The structure of an asparagine (N-) linked oligosaccharide of pokeweed lectin-B (PL-B) and the amino acid sequences around two glycosylation sites were identified. The pyridylamino (PA) oligosaccharide prepared from PL-B was eluted as a single peak on both reversed-phase (RP-) HPLC and size-fractionation (SF-) HPLC, and its structure was estimated to be Man alpha 1-->6(Man alpha 1-->3)(Xyl beta 1-->2) Man beta 1-->4GlcNAc beta 1-->4(Fuc alpha 1-->3)GlcNAc by a combination of component analysis, successive exoglycosidase digestions, IS-MS analysis, and 500 MHz 1H-NMR. Two tryptic glycopeptides were isolated from the reduced and S-pyridylethylated PL-B after gel filtration followed by RP-HPLC, indicating the presence of two glycosylation sites in PL-B. The amino acid sequences around the two glycosylation sites were determined to be Cys-Gly-Val-Asp-Phe-Gly-Asn(CHO)-Arg.
鉴定了商陆凝集素-B（PL-B）的天冬酰胺（N-）连接寡糖的结构以及两个糖基化位点周围的氨基酸序列。从PL-B制备的吡啶基氨基（PA）寡糖在反相（RP-）HPLC和尺寸分级（SF-）HPLC上均以单峰洗脱，通过组分分析、连续外切糖苷酶消化、串联质谱（IS-MS）分析和500 MHz 1H-NMR联用，估计其结构为Manα1→6（Manα1→3）（Xylβ1→2）Manβ1→4GlcNAcβ1→4（Fucα1→3）GlcNAc。经凝胶过滤后再进行RP-HPLC，从还原的和S-吡啶基乙基化的PL-B中分离出两个胰蛋白酶糖肽，表明PL-B中存在两个糖基化位点。确定两个糖基化位点周围的氨基酸序列为Cys-Gly-Val-Asp-Phe-Gly-Asn（CHO）-Arg。
