Verheijen F W, Janse H C, van Diggelen O P, Bakker H D, Loonen M C, Durand P, Galjaard H
Biochem Biophys Res Commun. 1983 Dec 16;117(2):470-8. doi: 10.1016/0006-291x(83)91224-x.
Human leucocytes contain two different MU-NANA neuraminidases, which can be distinguished by Concanavalin A binding. The Con A binding form is predominant in lymphocytes (more than 80%) and the non-binding form predominates in granulocytes. The pH optima of both these neuraminidases as well as their subcellular localization as determined by Percoll gradient centrifugation suggest that they are both lysosomal. Immunological studies indicate that the Con A binding form is present in a complex with beta-galactosidase whereas the non-binding form is not. Leucocytes from patients with sialidosis or galactosialidosis are deficient in the Con A binding neuraminidase, whereas the non-binding form is normal. In sialolipidosis both forms are normal. These results demonstrate that leucocytes contain at least two genetically different MU-NANA neuraminidases. Thus, the use of leucocytes should be avoided for the diagnosis of sialidosis and galactosialidosis, and isolated lymphocytes should be used to obtain reliable results.
人类白细胞含有两种不同的N-乙酰神经氨酸酶（MU-NANA），可通过伴刀豆球蛋白A结合来区分。伴刀豆球蛋白A结合形式在淋巴细胞中占主导（超过80%），非结合形式在粒细胞中占主导。这两种神经氨酸酶的最适pH值以及通过Percoll梯度离心确定的亚细胞定位表明它们都是溶酶体酶。免疫学研究表明，伴刀豆球蛋白A结合形式与β-半乳糖苷酶形成复合物，而非结合形式则不然。患有唾液酸沉积症或半乳糖唾液酸沉积症的患者的白细胞中缺乏伴刀豆球蛋白A结合神经氨酸酶，而非结合形式正常。在唾液脂质沉积症中，两种形式均正常。这些结果表明，白细胞至少含有两种基因不同的N-乙酰神经氨酸酶（MU-NANA）。因此，应避免使用白细胞来诊断唾液酸沉积症和半乳糖唾液酸沉积症，而应使用分离的淋巴细胞以获得可靠结果。
