Lactoperoxidase and hydrogen peroxide metabolism in the airway
Lactoperoxidase and hydrogen peroxide metabolism in the airway
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DOI：
10.1164/rccm.2206018
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发表时间：
2002-12-15
影响因子：
24.7
通讯作者：
Forteza, R
中科院分区：
文献类型：
--
作者：
Conner, GE;Salathe, M;Forteza, R
已知过氧化氢（H2O2）在气道稳态中起重要作用。由于这个原因，它的水平，因此它的合成和消耗是控制气道功能的重要机制。我们已经确定了主要的大分子消费者的过氧化氢在绵羊气道分泌物是乳过氧化物酶（LPO），血红素过氧化物酶以前在牛奶和唾液中的研究。这种酶使用H2O2将硫氰酸根阴离子氧化为抗生素化合物，以防止细菌，真菌和病毒的生长。从绵羊气道中分离出LPO，并证明其是气道分泌物中可溶性蛋白质的主要成分，约占1%。分离的气道LPO具有催化活性，并显示出先前描述的从牛乳中分离的酶的酶特性。气道LPO活性显示出增加绵羊气道细菌清除率。这种酶在气道宿主防御中的作用强烈表明存在活性H2O2产生系统，为酶提供适当的底物。该H2O2合成系统的身份是气道氧自由基代谢的重要但未知的特征。
Hydrogen peroxide (H2O2) is known to play an important role in airway homeostasis. For this reason its levels and thus its synthesis and consumption are important mechanisms for controlling airway functions. We have identified the major macromolecular consumer of H2O2 in sheep airway secretions to be lactoperoxidase (LPO), a heme peroxidase previously studied in milk and saliva. This enzyme uses H2O2 to oxidize the anion thiocyanate to an antibiotic compound that prevents growth of bacteria, fungi, and viruses. LPO was isolated from sheep airways and proved to be a major constituent comprising about 1% of the soluble protein in airway secretions. The isolated airway LPO was catalytically active and displayed the enzymatic characteristics previously described for the enzyme isolated from bovine milk. Airway LPO activity was shown to increase the rate of bacterial clearance from sheep airways. The role of this enzyme in the airway host defense strongly suggests that an active H2O2 production system exists to supply appropriate substrate for the enzyme. The identity of this H2O2 synthesis system is an important, yet unknown feature of airway oxygen radical metabolism.