Kaplan J
Science. 1981 Apr 3;212(4490):14-20. doi: 10.1126/science.6259730.
Polypeptide receptors on mammalian plasma membranes can be categorized on the basis of function. The binding of ligand by class I receptors results in changes in cell metabolism or behavior. Hormone-receptor interactions typify this group. The binding of ligand by class II receptors in ligand internalization. Although changes in cellular activity may result from metabolism of the internalized ligand, the interaction between ligand and class II receptor does not itself lead to alterations in cell behavior. Class II receptors include those for low-density lipoproteins and for alpha-macroglobulin-protease complexes. Although receptors within each category are chemically disparate, they show striking similarities in behavior. Analysis of the behavioral patterns of receptors in each category reveals insights into receptor physiology and allows for a prospective analysis of receptor characteristics.
哺乳动物质膜上的多肽受体可根据功能进行分类。I类受体与配体结合会导致细胞代谢或行为发生变化。激素与受体的相互作用是这一类别的典型代表。II类受体与配体结合会导致配体内化。尽管内化配体的代谢可能会引起细胞活性的变化，但配体与II类受体之间的相互作用本身并不会导致细胞行为的改变。II类受体包括低密度脂蛋白受体和α-巨球蛋白-蛋白酶复合物受体。尽管每一类受体在化学性质上各不相同，但它们在行为上却表现出惊人的相似性。对每一类受体行为模式的分析揭示了受体生理学的相关见解，并有助于对受体特征进行前瞻性分析。
