Sidhu R S, Bollon A P
Department of Molecular Genetics, Wadley Institutes of Molecular Medicine, Dallas, Texas 75235.
Anticancer Res. 1989 Nov-Dec;9(6):1569-76.
Truncated tumor necrosis factor analogs were produced by making in vitro deletions of the coding sequence of the human TNF gene. One of these analogs, TNF-desA7, lacked seven amino terminal residues of the mature TNF protein and the other two analogs, TNF-desC7 and TNF-desC2, had deletions of seven and two carboxy terminal amino acids, respectively. While the deletion of the first seven amino acid residues did not affect the biological activity of the protein, the deletions of carboxy terminal residues in both analogs resulted in the complete loss of biological activity. A direct correlation of the biological activity of the TNF protein and its binding to neutralizing monoclonal antibodies was observed. The carboxy terminal-deleted TNF analogs, with no biological activity, did not bind to neutralizing monoclonal antibodies while the amino terminal-deleted analog, which retained complete biological activity, did bind. These results indicate that the carboxy terminal amino acids of the TNF protein are essential for TNF biological activity and are part of an epitope recognized by neutralizing monoclonal antibodies.
通过对人肿瘤坏死因子（TNF）基因编码序列进行体外缺失，制备了截短的肿瘤坏死因子类似物。其中一种类似物TNF-desA7缺少成熟TNF蛋白的七个氨基末端残基，另外两种类似物TNF-desC7和TNF-desC2分别缺失了七个和两个羧基末端氨基酸。虽然缺失前七个氨基酸残基不影响该蛋白的生物活性，但两种类似物中羧基末端残基的缺失导致生物活性完全丧失。观察到TNF蛋白的生物活性与其与中和性单克隆抗体的结合之间存在直接相关性。没有生物活性的羧基末端缺失的TNF类似物不与中和性单克隆抗体结合，而保留完全生物活性的氨基末端缺失的类似物则能结合。这些结果表明，TNF蛋白的羧基末端氨基酸对于TNF生物活性至关重要，并且是中和性单克隆抗体识别的表位的一部分。
