Flavin‐Binding Sites in Phycomyces
Flavin‐Binding Sites in Phycomyces
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须霉菌中的黄素结合位点
DOI：
10.1111/j.1438-8677.1999.tb00276.x
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发表时间：
1999
期刊：
影响因子：
3.9
通讯作者：
R. Hertel
中科院分区：
文献类型：
--
作者：
R. Flores;A. Dederichs;E. Cerda´;R. Hertel
核黄素结合蛋白可能是Blakesleeanus的趋性光感受器。放射性标记的核黄素结合到膜相关和胞质位点。膜位点（约0.2-0.6nmol/g新鲜材料）具有高度特异性，对核黄素（还原条件下KD <1 μM，氧化条件下KD <1 μM）、FMN、玫瑰黄素和FAD的亲和力降低。这些结合位点的性质与高等植物相似，可以用温和的洗涤剂溶解，并且在真菌的所有营养部分（包括孢子）中发现。向光性缺陷的突变体在结合位点的量或其亲和力方面与野生型没有差异。一个完全不同的结合核黄素中观察到的sporangiophores的胞质上清液中，这种活动是耐热的结合位点可以部分纯化，并确认为没食子酸的聚合产物。黄色素在孢子囊柄（4.5nmol/g鲜质量）和孢子（60 nmol/g鲜质量）中含量丰富，但在洗过的膜中含量很少（0.02- 0.11nmol/g鲜质量）。自发荧光，其吸收和发射波长适合核黄素，被视为通过共聚焦显微镜，部分作为群集的颗粒，在活跃生长的菌丝体的部分，在孢囊的细胞质中，并在孢子。
: Riboflavin-binding proteins could be the photorecep-tors for tropism in the fungus Phycomyces blakesleeanus. Radio-labelled riboflavin bound to both membrane-associated and cy-tosolic sites. The membrane sites (approximately 0.2–0.6nmol per g fresh material) were highly specific, with decreasing affinities for riboflavin (KD≅ 1 μM under reducing conditions, KD≅μM under oxidizing conditions), FMN, roseoflavin, and FAD. These binding sites, whose properties were similar to those of higher plants, could be solubilized with mild detergents, and were found in all vegetative parts of the fungus, including the spores. Mutants defective for phototropism did not differ from the wild type in the amount of binding sites or their affinity. A completely different binding to riboflavin was observed in the cytosolic supernatant of the sporangiophores; this activity was heat resistant and the binding sites could be partially purified and recognized as a polymerization product of gallic acid. Flavms were abundant in the sporangiophores (4.5 nmol per g fresh mass) and the spores (60 nmol per g fresh mass), but scarce in washed membranes (0.02–0.11 nmol per g fresh spor-angiophore mass). Autogenous fluorescence, whose absorption and emission wavelengths fit those of riboflavin, was seen by confocal microscopy, in part as clustered particles, in the actively growing parts of the mycelium, in the cytoplasm of sporangiophores, and in the spores.
DOI：
10.1073/pnas.95.5.2686
发表时间：
1998-03-03
影响因子：
11.1
作者：
Lin, CT;Yang, HY;Cashmore, AR
通讯作者：
Cashmore, AR
影响因子：
56.9
作者：
Guo, HW;Yang, WY;Lin, CT
通讯作者：
Lin, CT
影响因子：
11.6
作者：
LISCUM, E;BRIGGS, WR
通讯作者：
BRIGGS, WR