Carp H
J Exp Med. 1982 Jan 1;155(1):264-75. doi: 10.1084/jem.155.1.264.
Mitochondria synthesize several hydrophobic proteins. Like bacteria, mitochondria initiate protein synthesis with an N-formylmethionine residue. Because N-formylmethionyl peptides have been found to be chemotactic for polymorphonuclear leukocytes (PMN), mitochondria isolated from cultured human cells and purified bovine mitochondrial proteins were tested for PMN chemotactic activity in vitro. Nondisrupted mitochondria were not chemotactic. However, intact mitochondria that had been incubated with a lysosomal lysate did stimulate PMN migration. Antibodies directed against two mitochondrial enzymes, cytochrome oxidase and ATPase, (both of which contain mitochondrially synthesized subunits) but not anti-C3 or anti-C5 decreased mitochondrially derived chemotactic activity. In addition, purified bovine mitochondrial N-formylmethionyl proteins stimulated PMN migration in vitro, whereas nonformylated mitochondrial proteins did not. Furthermore, the chemotactic activity of purified mitochondrial proteins and disrupted mitochondria was decreased by the formyl peptide antagonist butyloxycarbonyl-phenylalanine-leucine-phenylalanine-leucine-phenylalanine. Finally, disrupted mitochondria and purified mitochondrial proteins stimulated PMN-directed migration (chemotaxis), according to accepted criteria. In addition to other chemotactic factors, release of N-formylmethionyl proteins from mitochondria at sites of tissue damage, may play a role in the accumulation of inflammatory cells at these sites.
线粒体合成多种疏水蛋白。与细菌一样，线粒体以N-甲酰甲硫氨酸残基起始蛋白质合成。由于已发现N-甲酰甲硫氨酰肽对多形核白细胞（PMN）具有趋化作用，因此对从培养的人细胞中分离出的线粒体和纯化的牛线粒体蛋白进行了体外PMN趋化活性测试。未破坏的线粒体没有趋化作用。然而，与溶酶体裂解物孵育过的完整线粒体确实能刺激PMN迁移。针对两种线粒体酶（细胞色素氧化酶和ATP酶，二者均含有线粒体合成的亚基）的抗体可降低线粒体来源的趋化活性，但抗C3或抗C5抗体则无此作用。此外，纯化的牛线粒体N-甲酰甲硫氨酰蛋白在体外能刺激PMN迁移，而非甲酰化的线粒体蛋白则不能。此外，甲酰肽拮抗剂丁氧羰基-苯丙氨酸-亮氨酸-苯丙氨酸-亮氨酸-苯丙氨酸可降低纯化的线粒体蛋白和破碎线粒体的趋化活性。最后，根据公认标准，破碎的线粒体和纯化的线粒体蛋白可刺激PMN定向迁移（趋化作用）。除其他趋化因子外，线粒体在组织损伤部位释放N-甲酰甲硫氨酰蛋白可能在这些部位炎症细胞的聚集过程中起作用。
