Mehansho H, Carlson D M
J Biol Chem. 1983 May 25;258(10):6616-20.
A family of proline-rich proteins which contain over 40% proline and a glycoprotein were isolated from submandibular glands of isoproterenol-treated rats by extraction with 10% trichloroacetic acid and fractionation of the acid-soluble portion on Bio-Gel A-1.5m. The proline-rich proteins were subsequently separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Proteins were detected by formaldehyde fixation and Coomassie staining. After elution from the gels, amino acid compositions were determined. The family of proline-rich proteins (about six) appears to be qualitatively identical with a family of proteins from parotid glands of isoproterenol-treated rats (Muenzer J., Bildstein, C., Gleason, M., and Carlson, D. M. (1979) J. Biol. Chem. 254, 5623-5628, 5629-5634), except for a substantial change in the relative amount of each protein. An acid-soluble glycoprotein (GP-158) was not detected in extracts of submandibular glands of normal rats, but GP-158 was highly induced by isoproterenol treatment. This glycoprotein has an apparent Mr = 158,000 as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The major amino acids were Asx, 13%; Glx, 18%; Pro, 29% and Gly, 11%. GP-158 contained about 37% carbohydrate, and its sugar composition on a molar basis was mannose, 3.0; galactose, 2.1; N-acetylglucosamine, 3.5; fucose, 1.2; and sialic acid (N-glycolyl(4-O-acetyl)neuraminic acid), 0.9. N-Acetylgalactosamine was not detected. A glycopeptide isolated from GP-158 had the same sugar composition as GP-158. The amino acid sequence of the glycopeptide was shown to be Asp-Gly-(Asn)-Gln-Thr-Gln-Pro-Arg-Pro-(Gly-Pro). Only the parotid and submandibular glands of rats responded in this dramatic fashion to isoproterenol. The isoproterenol-treated rat is considered an appropriate model system for studying the overall effects of catecholamine beta-agonists on gene expression in these secretory tissues.
通过用10%三氯乙酸提取并在Bio-Gel A-1.5m上对酸溶性部分进行分级分离，从异丙肾上腺素处理的大鼠下颌下腺中分离出一类富含脯氨酸的蛋白质家族，这类蛋白质中脯氨酸含量超过40%，还分离出了一种糖蛋白。随后通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分离富含脯氨酸的蛋白质。通过甲醛固定和考马斯亮蓝染色检测蛋白质。从凝胶上洗脱后，测定氨基酸组成。富含脯氨酸的蛋白质家族（约六种）在性质上似乎与异丙肾上腺素处理的大鼠腮腺中的一类蛋白质相同（Muenzer J.、Bildstein C.、Gleason M.和Carlson D. M.（1979年）《生物化学杂志》254卷，5623 - 5628页，5629 - 5634页），只是每种蛋白质的相对含量有显著变化。在正常大鼠下颌下腺提取物中未检测到一种酸溶性糖蛋白（GP - 158），但异丙肾上腺素处理可高度诱导其产生。通过十二烷基硫酸钠聚丙烯酰胺凝胶电泳测定，这种糖蛋白的表观分子量为158,000。主要氨基酸为天冬氨酸（Asx），占13%；谷氨酸（Glx），占18%；脯氨酸（Pro），占29%；甘氨酸（Gly），占11%。GP - 158含有约37%的碳水化合物，其摩尔糖组成是甘露糖3.0、半乳糖2.1、N - 乙酰葡糖胺3.5、岩藻糖1.2和唾液酸（N - 糖基化（4 - O - 乙酰）神经氨酸）0.9。未检测到N - 乙酰半乳糖胺。从GP - 158分离出的一个糖肽与GP - 158具有相同的糖组成。该糖肽的氨基酸序列显示为天冬氨酸 - 甘氨酸 - （天冬酰胺） - 谷氨酰胺 - 苏氨酸 - 谷氨酰胺 - 脯氨酸 - 精氨酸 - 脯氨酸 - （甘氨酸 - 脯氨酸）。只有大鼠的腮腺和下颌下腺对异丙肾上腺素产生这种显著反应。异丙肾上腺素处理的大鼠被认为是研究儿茶酚胺β - 激动剂对这些分泌组织中基因表达的总体影响的合适模型系统。
