ISOLATION, CHARACTERIZATION AND IMMUNOLOCALIZATION OF A 53-KDAL DENTIN SIALOPROTEIN (DSP)
ISOLATION, CHARACTERIZATION AND IMMUNOLOCALIZATION OF A 53-KDAL DENTIN SIALOPROTEIN (DSP)
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DOI：
10.1016/s0934-8832(11)80030-2
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发表时间：
1992-11-01
期刊：
影响因子：
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通讯作者：
VANDIJK, S
中科院分区：
文献类型：
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作者：
BUTLER, WT;BHOWN, M;VANDIJK, S
我们从大鼠牙本质提取物中分离出一种富含唾液酸的蛋白质，并将其命名为牙本质唾液酸蛋白，DSP（以前称为95 K糖蛋白）。DSP富含天冬氨酸、谷氨酸、甘氨酸和丝氨酸，但不含半胱氨酸和磷酸盐。30%的碳水化合物含量包括约9%的唾液酸，表明存在几种N-糖苷和O-糖苷。沉降平衡分析得出Mr为52，570。基于此分子量，我们计算出DSP含有约350个氨基酸和75个单糖。通过自动Edman降解，前8个氨基酸的序列显示为：Ile-Pro-Val-Pro-Gln-Leu-Val-Pro。该序列的前3个残基与人骨桥蛋白（OPN）的前3个残基相同，与其他物种OPN的Leu-Pro-瓦尔序列以及骨酸性糖蛋白-75（BAG-75）的起始序列相似。同样，免疫定位实验显示DSP存在于牙本质中，但不在牙釉质或牙槽骨中。沿着其他地方报道的免疫组织化学定位数据，这些观察结果表明DSP可能是成牙本质细胞谱系中细胞的重要标志物。
We isolated a sialic-rich protein from rat dentin extracts and have named it dentin sialoprotein, DSP (formerly called 95K glycoprotein). DSP is rich in aspartic acid, glutamic acid, glycine and serine, but contains no cysteine or phosphate. The 30% carbohydrate content includes about 9% sialic acid and indicates that several N-glycosides and O-glycosides are present. Sedimentation equilibrium analysis gave a Mr of 52,570. Based on this molecular weight we calculated that DSP contains about 350-amino acids and 75 monosaccharides. With automated Edman degradation the sequence of the first 8-amino acids was shown to be: Ile-Pro-Val-Pro-Gln-Leu-Val-Pro. The initial 3 residues of this sequence are identical to the first 3 in human osteopontin (OPN) and are closely similar to the Leu-Pro-Val sequences of OPN from other species, as well as at the beginning of bone acidic glycoprotein-75 (BAG-75).On Western immunoblots, purified polyclonal antibodies reacted only with DSP in dentin extracts and with none of the proteins from bone. Similarly, immunolocalization experiments showed the presence of DSP in dentin but not in enamel or alveolar bone. Along with immunohistochemical localization data reported elsewhere, these observations suggest that DSP may be an important marker for cells in the odontoblast lineage.