Effect of melanization upon porosity of the cryptococcal cell wall
Effect of melanization upon porosity of the cryptococcal cell wall
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DOI：
10.1080/13693780412331271081
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发表时间：
2005-06-01
期刊：
影响因子：
2.9
通讯作者：
Ikeda, R
中科院分区：
文献类型：
--
作者：
Jacobson, ES;Ikeda, R
细胞壁成分黑色素是病原真菌的毒力因子，但其结构和机制作用尚不清楚。由于黑色素形成的中间体是交联剂，我们想知道黑化细胞壁是否可能比非黑化细胞壁交联程度更高且多孔性更少。真菌病原体新型隐球菌只有在外源儿茶酚存在的情况下才会产生黑色素；我们在有或没有 1 mmol/l 多巴胺的情况下培养它。我们通过在 10% 十二烷基硫酸钠中煮沸细胞来制备机械完整的黑化和非黑化细胞壁；电子显微镜显示细胞质破坏。我们将所得球体倒入柱中并研究分级葡聚糖的洗脱行为。高分子量葡聚糖比低分子量葡聚糖更早洗脱，而低分子量葡聚糖又在葡萄糖之前洗脱，这是尺寸排阻色谱的行为特征。我们计算了阈值，超过该阈值聚合物就被完全排除在细胞壁之外。黑化细胞的分子量阈值为 30 600，非黑化细胞为 270000（P
The cell-wall constituent, melanin, is a virulence factor for pathogenic fungi, but its structural and mechanistic role is not clearly understood. As intermediates in melanin formation are cross-linking agents, we wondered whether melanized cell walls might be more highly cross-linked and less porous than non-melanized cell walls. The fungal pathogen Cryptococcus neoformans makes melanin only in the presence of exogenous catechols; we cultivated it with and without 1 mmol/l dopamine. We prepared mechanically intact melanized and non-melanized cell walls by boiling cells in 10% sodium dodecyl sulfate; electron microscopy showed disruption of cytoplasm. We poured the resulting spheres into columns and studied the elution behavior of graded dextrans. High-molecular-weight dextrans eluted earlier than low-molecular-weight dextrans, which, in turn, eluted before glucose, behavior characteristic of size-exclusion chromatography. We calculated the thresholds above which the polymers were totally excluded from the cell walls. Melanized cells exhibited a threshold of molecular weight 30 600, non-melanized, 270000 (P