Role of Oligosyl Residue of Glycoprotein Solution in Viscosity Behavior

以天然的A_1卵清蛋白为原料，经内切- n -乙酰氨基糖酶处理，并用各种凝集素琼脂糖柱进行亲和层析，制备了具有两个磷酸化残基的A_1卵清蛋白。天然卵清蛋白不容易被胰蛋白酶水解，但SDS聚丙烯酰胺凝胶电泳显示，去糖基化的卵清蛋白被有限水解。随着胰蛋白酶的消化而出现的新片段估计大约有30,000和10,000的分子量。差示扫描量热法测定，去糖基化A蛋白的变性温度为71.8^ C，比A_1蛋白的变性温度低0.8^ C。A和去糖基化A_1卵清蛋白（0.40 mg/mL）具有不同的浊度- ph谱。在pH值下，去糖基化的卵清蛋白峰出现，吸热面积比A_1的更宽，说明去糖基化降低了A_1卵清蛋白的疏水性。从注射透霉素的母鸡输卵管中纯化非糖基化卵清蛋白。用结晶和凝集素柱层析相结合的方法纯化了非糖基化卵清蛋白和糖基化卵清蛋白。从注射了tunicamycin的母鸡中获得的非糖基化卵白蛋白具有不同的磷酸化模式。也就是说，A_1、A_2、A_3卵清蛋白的比例发生了变化。采用DEAE纤维素层析分离分离了非糖基化和糖基化的A_1卵清蛋白。在低剪切速率区，非糖基化A_1卵清蛋白溶液的表观粘度高于糖基化A_1卵清蛋白溶液。这意味着糖蛋白的糖部分降低了低剪切速率区域的粘度。非糖基化A_1卵清蛋白表现出较低的热稳定性和对胰蛋白酶的敏感性。

Deglycosylated A_1 ovalbumin with two phosphoryl residues in the molecule was prepared from native A_1 ovalbumin by endo-beta-N-acetylglycosamidase treatment and successive affinity chromatography using various lectin agarose columns. Native ovalbumin is not susceptible to be hydrolyzedby trypsin, however, deglycosylated ovalbumin was limited-hydrolyzed, being shown by SDS polyacrylamide gel electrophoresis. The new fragments appeared with the digestion of trypsin had about 30,000 and 10,000 of molecular weight estimated. Using the differential scanning calorimetric meassurement, the denaturation temperature of the deglycosylated A ovalbumin was 71.8^ﾟC which was lower than that of the A_1 ovalbumin by 0.8^ﾟC. A and deglycosylated A_1 ovalbumin (0.40 mg/mL) have different turbidity-pH profiles. The peak of deglycosylated ovalbumin was found at pH and the endothermic area was broader than that of the A_1 ovalbumin, indicating the hydrophobicity of A_1 ovalbumin decrease by deglycosylation.Non-glycosylated ovalbumin was purified from the oviduct of the hen to which tunlcamycin was injected. Non-glycosylated ovalbmin and glycosylated ovalbumin was purified with a combination of the crystalization and lectin column chromatography. Non-glycosylated ovalbumin obtained from the hen injected tunicamycin was a different phosphorylated pattern. That is, the ratio of the A_1, A_2, and A_3 ovalbumin was changed. Non-glycosylated and glycosyslated A_1 ovalbumin were separated and isolated by DEAE cellulose chromatography. The apparent viscosity of non-glycosylated A_1 ovalbumin solution was higher in a low shear rate region than that of glycosylated A_1 ovalbumin solution. This means that the glyco part of the glycoprotein reduces the viscosity at low shear rate region. Non-glycosylated A_1 ovalbumin showed low heat stability and high susceptibility to trypsin.