Yan Z, Holt J C, Stewart G J, Niewiarowski S
Department of Physiology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140.
Am J Physiol. 1993 Nov;265(5 Pt 1):C1396-404. doi: 10.1152/ajpcell.1993.265.5.C1396.
A new member of the cytokine intercrine alpha-subfamily, porcine neutrophil-activating peptide 2 (pNAP-2), was isolated to homogeneity. Amino acid sequencing analysis showed two species of pNAP-2, a long form (pNAP-2-L) and a short form (pNAP-2-S). pNAP-2-L had seven more amino acids at the NH2-terminus than pNAP-2-S. The remaining amino acid sequences of the two molecules were identical. pNAP-2-S shared 65% homology with human neutrophil-activating peptide 2 (hNAP-2) including four cysteines in identical positions. Moreover, the NH2-terminal sequence Glu-Leu-Arg (E-L-R) was conserved in both molecules. Both pNAP-2-L and pNAP-2-S induced mobilization of cytosolic calcium in neutrophils and caused release of granulocyte elastase in a dose-dependent manner, although pNAP-2-L was less active. A desensitization study suggested that both hNAP-2 and pNAP-2-S may act on the same receptor. Whereas human platelets release inactive precursors that can be converted to hNAP-2 by cathepsin G from activated neutrophils, porcine platelets, upon stimulation with thrombin, appear to secrete active forms of pNAP-2. The activated neutrophils are not involved in the generation of pNAP-2.
细胞因子白细胞介素α亚家族的一个新成员——猪中性粒细胞激活肽2（pNAP - 2）被分离纯化至均一状态。氨基酸序列分析显示有两种形式的pNAP - 2，一种长形式（pNAP - 2 - L）和一种短形式（pNAP - 2 - S）。pNAP - 2 - L在NH2末端比pNAP - 2 - S多七个氨基酸。这两种分子的其余氨基酸序列相同。pNAP - 2 - S与人类中性粒细胞激活肽2（hNAP - 2）有65%的同源性，包括四个处于相同位置的半胱氨酸。此外，NH2末端序列Glu - Leu - Arg（E - L - R）在两种分子中均保守。尽管pNAP - 2 - L活性较低，但pNAP - 2 - L和pNAP - 2 - S均可诱导中性粒细胞胞质钙动员，并以剂量依赖方式导致粒细胞弹性蛋白酶释放。脱敏研究表明hNAP - 2和pNAP - 2 - S可能作用于同一受体。人类血小板释放无活性前体，可被活化中性粒细胞中的组织蛋白酶G转化为hNAP - 2，而猪血小板在凝血酶刺激下似乎分泌活性形式的pNAP - 2。活化的中性粒细胞不参与pNAP -
