植物细胞中间纤维角蛋白性质的分析

角蛋白是植物细胞中间纤维的主要成分。应用选择性抽提和生物化学技术,分离纯化了豌豆根尖细胞58-、52 kD、白菜子叶52kD和胡萝卜悬浮细胞64kD角蛋白,测定了它们的氨基酸组成,结果表明上述角蛋白与动物细胞中间纤维角蛋白的氨基酸组成有较大的相似性。比较了动、植物细胞角蛋白的肽谱,结果显示它们之间存在较大的差异,但是植物细胞间角蛋白的肽谱比较一致,这提示它们属于同一蛋白家族,为植物中间纤维及其角蛋白的存在提供了新的论据。

ANALYSIS OF THE PROPERTIES OF KERATINS IN HIGHER PLANT CELLS

Keratins are main components of the intermediate filaments (IFs) in higher plant cells. By selective extraction and biochemical techniques, we purified the 58 KD and 52 KD keratins in soybean root tip cells, 52 KD keratin in cabbage cotyledon cells and 64 KD keratin in carrot suspension cells. The amino acid compositions of these polypeptides were determined and showed much similarity. The datarevealed no much difference from those of keratins in animal cells. The peptide maps of plant IF keratins, though different from those of animal IF keratins, are also similar. This suggests that the plant IF keratins may belong to the same protein family in higher plant cells. These results provide new evidences for the existence of intermediate filaments and keratins in higher plant cells.