EXTRACELLULAR FOLATE DEAMINASE OF DICTYOSTELIUM-DISCOIDEUM
EXTRACELLULAR FOLATE DEAMINASE OF DICTYOSTELIUM-DISCOIDEUM
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DOI：
10.1016/0304-4165(81)90099-4
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发表时间：
1981-01-01
期刊：
影响因子：
--
通讯作者：
VANDRIEL, R
中科院分区：
文献类型：
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作者：
BERNSTEIN, RL;TABLER, M;VANDRIEL, R
从 D. discoideum 细胞中释放的叶酸脱氨酶 [一种在生长过程中充当化学引诱剂的酶] 在分子量和 60°C 稳定性方面具有异质性。 C. 最热稳定的组分在大约 .apprx 的宽带中等电聚焦。 pH 6。该成分对叶酸的 Km 值为 .apprx。 7.10-7 M 和 MW 约40,000。大部分（如果不是全部）脱氨酶与固定的刀豆球蛋白 A 和扁豆凝集素结合。细胞外叶酸脱氨酶的最适 pH 值为 .apprx。 pH值6.0。这高于溶酶体酶，溶酶体酶也是释放到细胞外介质中的糖蛋白。
Folate deaminase [an enzyme that acts as a chemo-attractant during growth] released from cells of D. discoideum is heterogeneous with respect to MW and stability at 60.degree. C. The most heat-stable component isoelectrofocuses in a broad band at .apprx. pH 6. The Km value of this component for folate is .apprx. 7.10-7 M and MW .apprx. 40,000. The major portion if not all of the deaminase binds to immobilized concanavalin A and lentil lectin. Extracellular folate deaminase has a pH-optimum of .apprx. pH 6.0. This is higher than that of lysosomal enzymes, which are also glycoproteins released into the extracellular medium.