Tams J W, Welinder K G
Department of Protein Chemistry, Institute of Molecular Biology, University of Copenhagen, Denmark.
FEBS Lett. 1998 Jan 16;421(3):234-6. doi: 10.1016/s0014-5793(97)01573-1.
The influence of N-linked glycans on the stability of glycoproteins has been studied using horseradish peroxidase isoenzyme C (HRP), which contains eight asparagine-linked glycans. HRP was deglycosylated (d-HRP) with trifluoromethanesulfonic acid and purified to an enzymatically active homogeneous protein containing (GlcNAc)2 glycans. The thermal stability of HRP and d-HRP at pH 6.0, measured by residual activity, was indistinguishable and showed transition midpoints at 57 degrees C, whereas the unfolding in guanidinium chloride at pH 7.0, 23 degrees C was 2-3-fold faster for d-HRP than for HRP. The results are compatible with a glycan-induced decrease in the dynamic fluctuation of the polypeptide chain.
已使用含有八个天冬酰胺连接聚糖的辣根过氧化物酶同工酶C（HRP）研究了N-连接聚糖对糖蛋白稳定性的影响。用三氟甲磺酸对HRP进行去糖基化处理（d-HRP），并纯化得到含有（GlcNAc）2聚糖的具有酶活性的均一蛋白。通过残余活性测量，HRP和d-HRP在pH 6.0时的热稳定性没有差异，转变中点温度为57℃，而在pH 7.0、23℃的氯化胍中展开时，d-HRP的速度比HRP快2至3倍。这些结果与聚糖引起的多肽链动态波动降低相一致。
