Influence of carbohydrate on structure, stability, and function of gelatin-binding fragments of fibronectin.
Influence of carbohydrate on structure, stability, and function of gelatin-binding fragments of fibronectin.
复制标题
碳水化合物对纤连蛋白明胶结合片段的结构、稳定性和功能的影响。
DOI：
10.1006/abbi.1995.1033
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Novokhatny,VV
中科院分区：
文献类型：
--
作者：
Ingham,KC;Brew,SA;Novokhatny,VV
纤维连接蛋白的明胶结合区包含三个Asn-linked碳水化合物片段，一个在第二个II型模块上，两个在第八个I型“手指”模块上。碳水化合物基团被酶从两个不重叠的明胶结合片段（GBF）上去除，21-kDa的GBF（模块化组成I8-I9）和30-kDa的GBF（模块化组成i6 - i1 - i2 - i7），难度更大。这些片段的明胶结合特性仅受到轻微影响或根本不受影响。荧光和量热分析表明，模块i8被去糖基化强烈地破坏了稳定性，使载脂蛋白形式在接近生理温度时融化。将holo形式的pH降低到6.0也会产生类似的效果，这表明一种或多种组氨酸对模块I8的稳定性很重要。21 kda片段在较高的pH值下表现出酸诱导的荧光变化，进一步证明了一个或两个碳水化合物部分具有稳定作用。相比之下，模组ii2的稳定性不受去除其单一碳水化合物的影响。碳水化合物对模块i8的稳定性的影响可能对在细菌中表达它或含有它的片段的努力是重要的。
The gelatin-binding region of fibronectin contains three Asn-linked carbohydrate moieties, one on the second type II module and two on the eighth type I "finger" module. Carbohydrate groups were enzymatically removed from two nonoverlapping gelatin-binding fragments (GBFs), 21-kDa GBF (modular composition I8-I9) and, with much greater difficulty, 30-kDa GBF (modular composition I6-II1-II2-I7). The gelatin-binding properties of these fragments were affected only slightly or not at all. Fluorescence and calorimetric analyses indicated that module I8was strongly destabilized by deglycosylation such that the apo form melts near physiological temperature. A similar effect was caused by decreasing the pH of the holo form to 6.0, suggesting that one or more histidines are important for stability of module I8. The 21-kDa fragment exhibited an acid-induced change in fluorescence that occurred at higher pH in the deglycosylated derivative, providing further evidence of a stabilizing role for one or both carbohydrate moieties. By contrast, the stability of module II2was unaffected by removal of its single carbohydrate. The effects of carbohydrate on the stability of module I8may be important in efforts to express it or fragments containing it in bacteria.