Woolfolk C A, Downard J S
J Bacteriol. 1977 Jun;130(3):1175-91. doi: 10.1128/jb.130.3.1175-1191.1977.
A diverse collection of xanthine-metabolizing bacteria was examined for xanthine-, 1-methylxanthine-, and 3-methylxanthine-oxidizing activity. Both particulate and soluble fractions of extracts from aerobically grown gram-negative bacteria exhibited oxidation of all three substrates; however, when facultative gram-negative bacteria were grown anaerobically, low particulate and 3-methylxanthine activities were detected. Gram-positive and obligately anaerobic bacteria showed no particulate activity or 3-methylxanthine oxidation. Substrate specificity studies indicate two types of enzyme distributed among the bacteria along taxonomic lines, although other features indicate diversity of the enzyme within these two major groups. The soluble and particulate enzymes from Pseudomonas putida and the enzyme from Arthrobacter S-2 were examined as type examples with a series of purine and analogues differing in the number and position of oxygen groups. Each preparation was active with a variety of compounds, but the compounds and position attacked by each enzyme was different, both from the other enzymes examined and from previously investigated enzymes. The soluble enzyme from Pseudomonas was inhibited in a competitive manner by uric acid, whereas the Arthrobacter enzyme was not. This was correlated with the ability of Pseudomonas, but not Arthrobacter, to incorporate radioactivity from [2-14C]uric acid into cellular material.
对多种黄嘌呤代谢细菌进行了黄嘌呤、1-甲基黄嘌呤和3-甲基黄嘌呤氧化活性检测。需氧生长的革兰氏阴性菌提取物的颗粒部分和可溶部分均表现出对所有三种底物的氧化作用；然而，兼性革兰氏阴性菌在厌氧条件下生长时，颗粒部分活性较低，且仅检测到3-甲基黄嘌呤的氧化活性。革兰氏阳性菌和专性厌氧菌未表现出颗粒部分活性或3-甲基黄嘌呤氧化活性。底物特异性研究表明，尽管其他特征表明这两类主要菌群内的酶具有多样性，但沿着分类学线在细菌中分布着两种类型的酶。以恶臭假单胞菌的可溶酶和颗粒酶以及节杆菌S-2的酶作为典型例子，检测了一系列在氧基团数量和位置上不同的嘌呤及其类似物。每种制剂对多种化合物均有活性，但每种酶作用的化合物及其作用位置均不同，既不同于所检测的其他酶，也不同于先前研究过的酶。恶臭假单胞菌的可溶酶受到尿酸的竞争性抑制，而节杆菌的酶则不受抑制。这与恶臭假单胞菌（而非节杆菌）将[2-14C]尿酸中的放射性掺入细胞物质的能力相关。
