MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824-1312.
Plant Physiol. 1989 Oct;91(2):473-6. doi: 10.1104/pp.91.2.473.
Wheat germ agglutinin (WGA) is synthesized as a proprotein with a glycosylated, 15 amino acid, carboxyl-terminal propeptide. This glycopeptide is cleaved from pro-WGA to produce the mature lectin during the transport of WGA to the protein bodies/vacuoles. To study the posttranslational modification of WGA, it would be useful to be able to differentiate between pro-WGA and mature WGA. Therefore, a peptide corresponding to the propeptide of WGA was synthesized (WGA-B 172-186), and an antiserum was raised in rabbits (anti-WGA-B 172-186). Anti-WGA-B 172-186 reacted with pure WGA-B 172-186 and pro-WGA in ELISA. Anti-WGA-B 172-186 was also specific for and readily differentiated between pro-WGA and mature WGA on Western blots. This provided an assay to monitor pro-WGA on Western blots before and after endo-beta-N-acetylglucosaminidase H digestion. Using this assay, direct evidence was obtained that the oligosaccharide of pro-WGA is of the high-mannose type.
麦胚凝集素(WGA)作为一种前蛋白合成,具有糖基化的 15 个氨基酸的羧基末端前肽。在 WGA 向蛋白体/液泡运输过程中,该糖肽从前 WGA 中被切割下来,产生成熟的凝集素。为了研究 WGA 的翻译后修饰,如果能够区分前 WGA 和成熟 WGA,将是非常有用的。因此,合成了对应于 WGA 前肽的肽(WGA-B 172-186),并在兔子中产生了抗血清(抗-WGA-B 172-186)。抗-WGA-B 172-186 在 ELISA 中与纯 WGA-B 172-186 和前 WGA 反应。抗-WGA-B 172-186 还特异性地识别并在 Western blot 上很容易区分前 WGA 和成熟 WGA。这提供了一种在内切-β-N-乙酰氨基葡萄糖苷酶 H 消化前后监测 Western blot 上前 WGA 的测定方法。使用该测定法,直接获得了前 WGA 的寡糖是高甘露糖型的证据。