Nakamura C V, Esteves M J, Andrade A F, Alviano C S, de Souza W, Angluster J
Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, Brasil.
Parasitol Res. 1993;79(6):523-6. doi: 10.1007/BF00931596.
The occurrence of chitin as a structural component of the surface of the phytopathogenic protozoan Phytomonas françai was demonstrated by paper and gas-liquid chromatographic analysis of the products of enzymatic and chemical hydrolysis of alkali-resistant polysaccharides, lectin binding, glycosidase digestion, and infrared spectra. Chitin was characterized by its insolubility in hot alkali and chromatographic immobility as well as by the release of glucosamine on hydrolysis with strong acid and of N-acetylglucosamine (GlcNAc) on hydrolysis with chitinase. The presence of chitin was also shown directly by binding of wheat-germ agglutinin (WGA), which recognizes GlcNAc units, to the parasite surface. Fluorescein-labeled WGA binding was completely abolished by treatment with chitinase. This effect was specific since it could be prevented by incubating the enzyme with chitin before treatment of the phytomonads. These findings indicate that chitin is an exposed cell-surface polysaccharide in Phytomonas françai. The data were confirmed by the infrared spectrum of an alkali-insoluble residue, which showed a pattern typical of chitin.
通过对耐碱多糖的酶解和化学水解产物进行纸色谱和气相色谱分析、凝集素结合、糖苷酶消化以及红外光谱分析，证实了几丁质作为植物病原原生动物法氏植鞭毛虫表面结构成分的存在。几丁质的特征在于其在热碱中不溶且在色谱中不移动，以及在用强酸水解时释放出葡糖胺，在用几丁质酶水解时释放出N - 乙酰葡糖胺（GlcNAc）。通过识别GlcNAc单元的麦胚凝集素（WGA）与寄生虫表面的结合，也直接证明了几丁质的存在。用几丁质酶处理后，荧光素标记的WGA结合完全消失。这种效应是特异性的，因为在处理植鞭毛虫之前，将酶与几丁质一起孵育可以防止这种情况。这些发现表明几丁质是法氏植鞭毛虫中一种暴露的细胞表面多糖。碱不溶性残渣的红外光谱证实了这些数据，该光谱显示出典型的几丁质图谱。
