Reilly T J, Baron G S, Nano F E, Kuhlenschmidt M S
Department of Pathobiology, College of Veterinary Medicine, University of Illinois, Urbana 61801, USA.
J Biol Chem. 1996 May 3;271(18):10973-83. doi: 10.1074/jbc.271.18.10973.
Acid phosphatases (Acp) of intracellular pathogens have recently been implicated as virulence factors that enhance intracellular survival through suppression of the respiratory burst. We describe here the identification, purification, characterization, and sequencing of a novel burst-inhibiting acid phosphatase from the facultative intracellular bacterium, Francisella tularensis. Similar to other the burst-inhibiting Acps, F. tularensis Acp (AcpA) is tartrate-resistant and has broad substrate specificity. The AcpA enzyme is unique, however, in that it is easily released from the bacterial cell in soluble form, is a basic enzyme, suppresses the respiratory burst of not only fMet-Leu-Phe but also phorbol 12-myristate 13-acetate-stimulated neutrophils and does not fit into any of the three currently recognized classes of acid phosphatase. We also report the complete nucleotide sequence of the gene acpA, encoding AcpA, and the deduced primary structure of its encoded polypeptide. Comparative sequence analyses of AcpA is discussed. To our knowledge, this is the first report describing the cloning and sequencing of a burst-inhibiting acid phosphatase.
细胞内病原体的酸性磷酸酶（Acp）最近被认为是一种毒力因子，可通过抑制呼吸爆发来提高细胞内存活率。我们在此描述了从兼性细胞内细菌土拉弗朗西斯菌中鉴定、纯化、表征和测序一种新型的抑制爆发的酸性磷酸酶。与其他抑制爆发的Acp类似，土拉弗朗西斯菌Acp（AcpA）对酒石酸具有抗性且具有广泛的底物特异性。然而，AcpA酶的独特之处在于它很容易以可溶形式从细菌细胞中释放出来，是一种碱性酶，不仅能抑制甲酰甲硫氨酸-亮氨酸-苯丙氨酸诱导的呼吸爆发，还能抑制佛波酯12-肉豆蔻酸酯13-乙酸酯刺激的中性粒细胞的呼吸爆发，并且不属于目前公认的三类酸性磷酸酶中的任何一类。我们还报告了编码AcpA的基因acpA的完整核苷酸序列及其编码多肽的推导一级结构。讨论了AcpA的比较序列分析。据我们所知，这是第一份描述抑制爆发的酸性磷酸酶克隆和测序的报告。
