Strobel G, van Alfen N, Hapner K D, McNeil M, Albersheim P
Biochim Biophys Acta. 1978 Jan 3;538(1):60-75. doi: 10.1016/0304-4165(78)90252-0.
Ceratocystis ulmi, the causal agent of Dutch Elm Disease, produces phytotoxic glycopeptides in culture. A mixture of phytotoxic glycopeptides has been prepared by affinity chromatography on a concanavalin A-Sepharose column and collectively they have been termed the toxin. The polydisperse component that makes up the majority of toxin (80%) by weight has a molecular weight of about 2.7.10(5). The large molecular weight component (less than 5%) elutes at the void volume of a Bio-Gel A 50 m column. The other component (15%) appears as a trailing peak on the edge of the major component and has an approximate molecular weight of 7.10(4). The toxin is composed of 83% sugar residues, primarily rhamnose and mannose, and 7% amino acid residues. Methylation analysis coupled with mild acid hydrolysis indicates that the backbone of the polysaccharide portion of the toxin is composed of alpha -1,6-linked mannosyl residues with a 3-linked terminal rhamnosyl residue linked to C-3 of almost every mannosyl residue. The carbohydrate portion of the molecule is linked to the peptide via O-glycosidic linkages to both threonyl and seryl residues. All three components of the toxin are capable of causing wilt in stem cuttings of American elm.
榆枯萎病菌（Ceratocystis ulmi）是荷兰榆树病的致病因子，它在培养过程中会产生具有植物毒性的糖肽。通过在伴刀豆球蛋白A - 琼脂糖柱上进行亲和层析制备了一种具有植物毒性的糖肽混合物，它们被统称为毒素。构成毒素大部分（80%重量）的多分散成分的分子量约为2.7×10⁵。大分子成分（小于5%）在Bio - Gel A 50 m柱的空体积处洗脱。另一种成分（15%）在主要成分边缘呈现为拖尾峰，其近似分子量为7×10⁴。该毒素由83%的糖残基（主要是鼠李糖和甘露糖）和7%的氨基酸残基组成。甲基化分析结合温和酸水解表明，毒素多糖部分的主链由α - 1,6 - 连接的甘露糖基残基组成，几乎每个甘露糖基残基的C - 3连接有一个3 - 连接的末端鼠李糖基残基。分子的碳水化合物部分通过O - 糖苷键与苏氨酸和丝氨酸残基连接到肽上。毒素的所有三种成分都能够导致美国榆茎插条枯萎。
