Isolation and physicochemical characterization of soluble scleroglucan from Sclerotium rolfsii.: Rheological properties, molecular weight and conformational characteristics
Isolation and physicochemical characterization of soluble scleroglucan from Sclerotium rolfsii.: Rheological properties, molecular weight and conformational characteristics
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DOI：
10.1016/s0144-8617(00)00189-2
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发表时间：
2001-01-01
影响因子：
11.2
通讯作者：
Perotti, NI
中科院分区：
文献类型：
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作者：
Fariña, JI;Siñeriz, F;Perotti, NI
由白绢病菌ATCC 201126产生的硬葡聚糖表现出假塑性行为，表观粘度与聚合物浓度之间呈指数关系。粘度表现出较强的热稳定性（100 ℃/60 min）。耐受性高达20%w/v的NaCl和在宽的pH范围内（0-13）也被发现。一个急剧下降的粘度在NaOH浓度高于0.15 M时，观察到由于三螺旋的解离。根据特性粘度测定和Sepharose CL-4 B上的凝胶过滤色谱，天然多糖的重均分子量对于三聚体为约5 × 10（6）Da，对于无规卷曲为约1.6 × 10（6）Da。除了与刚果红络合的变化外，这些值支持中性或弱碱性溶液中三螺旋构象的想法（
Scleroglucan produced by Sclerotium rolfsii ATCC 201126 exhibited pseudoplastic behaviour and an exponential relationship between apparent viscosity and polymer concentration. Viscosity showed strong heat-stability (100 degreesC/60 min). Tolerance up to 20% w/v NaCl and over a wide pH range (0-13) was also found. A sharp decrease on viscosity at NaOH concentrations higher than 0.15 M was observed due to dissociation of the triple-helix. According to intrinsic viscosity determinations and gel filtration chromatography on Sepharose CL-4B, the weight-average molecular weight of native polysaccharide was about 5 x 10(6) Da for the tripler and 1.6 x 10(6) Da for the random coil. These values, in addition to the change in complexation with Congo Red, support the idea of the triple-helical conformation in neutral or slightly alkaline solutions (