Roberts R M
Plant Physiol. 1970 Mar;45(3):263-7. doi: 10.1104/pp.45.3.263.
d-Glucosamine-1-(14)C was rapidly taken up from aqueous solution by both excised bean (Phaseolus vulgaris) and corn (Zea mays) root tips. The labeled glucosamine did not accumulate in the tissues, however, but was metabolized to N-acetyl-d-glucosamine, N-acetyl-d-glucosamine phosphates, and uridine diphosphate N-acetyl-d-glucosamine. Little or no label was detected in respiratory CO(2), glycolytic intermediates, or d-glucosamine 6-phosphate. Between 5 and 10% of the (14)C was recovered in high molecular weight ethanol-insoluble materials which could be solubilized readily with alkali or by treatment with proteases, and which yielded labeled glucosamine upon complete hydrolysis with HCl. Milder hydrolytic conditions released quantities of N-acetylglucosamine-(14)C plus labeled fragments of higher molecular weight. It is concluded that d-glucosamine-(14)C may be used to label specifically the amino sugar residues of plant as well as animal macromolecules. N-Acetyl-d-glucosamine acts similarly as a precursor, except that it is taken up at only about 1/10 the rate of glucosamine and hence is utilized less efficiently.
d-葡萄糖胺-1-(14)C 能被切除的菜豆（菜豆属）和玉米（玉米属）根尖从水溶液中迅速吸收。然而，标记的葡萄糖胺并未在组织中积累，而是被代谢为 N-乙酰-d-葡萄糖胺、N-乙酰-d-葡萄糖胺磷酸酯和尿苷二磷酸 N-乙酰-d-葡萄糖胺。在呼吸产生的二氧化碳、糖酵解中间产物或 d-葡萄糖胺 6-磷酸中几乎检测不到或未检测到标记。在高分子量乙醇不溶性物质中回收了 5%至 10%的(14)C，这些物质可用碱或蛋白酶处理轻易溶解，并在用盐酸完全水解后产生标记的葡萄糖胺。较温和的水解条件会释放出一定量的 N-乙酰葡萄糖胺-(14)C 以及更高分子量的标记片段。结论是 d-葡萄糖胺-(14)C 可用于特异性标记植物和动物大分子中的氨基糖残基。N-乙酰-d-葡萄糖胺的作用类似，只是其吸收速率仅为葡萄糖胺的约 1/10，因此利用效率较低。
