Identification of twelve O-glycosylation sites in equine chorionic gonadotropin β and equine luteinizing hormone β by solid-phase Edman degradation
Identification of twelve O-glycosylation sites in equine chorionic gonadotropin β and equine luteinizing hormone β by solid-phase Edman degradation
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DOI：
10.1095/biolreprod64.1.136
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发表时间：
2001-01-01
影响因子：
3.6
通讯作者：
Butnev, VY
中科院分区：
文献类型：
--
作者：
Bousfield, GR;Butnev, VY;Butnev, VY
马LH β（eLH β）和eCG β的O-糖基化位点通过固相Edman降解C-末端区域的4种糖肽鉴定。两个亚基在相同的12个位置上被O-糖基化，而不是预期的4-6个位点。这些位点被部分糖基化，eCG β的碳水化合物连接范围为20%至100%，eLH β的碳水化合物连接范围为10%至100%。当通过对eLH β或eCG β进行温和的酸水解除去含有除一种外的所有O-连接寡糖的C-末端肽时，可以通过将eLH α、eFSH α或eCG α与截短的β亚基衍生物重新结合来获得杂合激素。当des（121-149）eLH β或des（121 - 149）eCG β与相同的α亚单位制剂组合时，这些杂合激素在LH受体结合活性方面相同。因此，O-糖基化似乎是β亚单位对eLH和eCG之间LH受体结合活性的实质性差异的贡献，马LH/CG β序列与灵长类CG β亚基序列的比较表明，前者的糖基化模式具有更大的保守性。
The O-glycosylation sites for equine LH beta (eLH beta) and eCG beta were identified by solid-phase Edman degradation of four glycopeptides derived from the C-terminal region. Both subunits were O-glycosylated at the same 12 positions, rather than the 4-6 sites anticipated, These sites were partially glycosylated, with carbohydrate attachment ranging from 20% to 100% for eCG beta and from 10% to 100% for eLH beta. When the C-terminal peptide containing all but one of the O-linked oligosaccharides was removed by mild acid hydrolysis of either eLH beta or eCG beta, hybrid hormones could be obtained by reassociating eLH alpha, eFSH alpha, or eCG alpha with the truncated beta subunit derivatives. These hybrid hormones were identical in LH receptor-binding activity when des(121-149)eLH beta or des(121-149)eCG beta were combined with the same alpha subunit preparation, Thus, O-glycosylation appears to be responsible for the beta subunit contribution to the substantial difference in LH receptor-binding activity between eLH and eCG, Comparison of the equid LH/CG beta sequences with those available for the primate CG beta subunits indicated a greater conservation of glycosylation patterns in the former.