Aminopeptidases in Caenorhabditis elegans and Panagrellus redivivus: detection using peptide and non-peptide substrates
Aminopeptidases in Caenorhabditis elegans and Panagrellus redivivus: detection using peptide and non-peptide substrates
复制标题
DOI：
10.1079/joh200193
复制
发表时间：
2002-03
影响因子：
1.6
通讯作者：
E. Masler
中科院分区：
文献类型：
--
作者：
E. Masler
摘要以L-丙氨酸-4-硝基苯胺为底物，检测了线虫线虫和黑线线虫提取液中氨基肽酶的活性。在Km(线虫=2.2 2 mm)和比活力(线虫=1.3 8±0.4 3Maumin-1μg-1；红线线虫(1.2 3±0.18Mau min-1μg-1))上有相似之处。两者均被阿司他丁竞争性抑制(线虫IC50=0.46μm；红曲霉IC50=15.90μm)，并被亮氨酸非竞争性抑制(线虫IC50=3.00μm；红曲霉IC50=37.35μm)。生物活性多肽、动脂激素和P物质降低了各提取物的表观氨基肽酶活性，表明这些多肽作为底物与ALA-PNA竞争。对于每种提取物，脂肪运动激素似乎是更有效的底物。在存在和不存在1 mM阿司他丁的情况下，线虫和雷氏线虫提取物对脂肪运动激素的消化产生了不同的层析图谱，表明这两个物种的消化模式不同。然而，阿司他丁对每个物种的层析图谱都有明显的影响，表明氨基肽酶参与了多肽底物的消化。这些数据表明，自由生活线虫的提取物能够代谢多肽激素，这种代谢涉及底物选择性氨基肽酶。
Abstract Aminopeptidase activities were detected in extracts of the free-living nematodes Caenorhabditis elegans and Panagrellus redivivus using the aminoacyl substrate L-alanine-4-nitroanilide. The activities exhibited similarities in Km (C.elegans = 2.22 mM; P.REDIVIVUS = 2.09 Mm) and specific activity (C. elegans=1.38±0.43 mAU min-1 μg-1; P. redivivus, 1.23±0.18 mAU min-1 μg-1). Each is inhibited competitively by amastatin (C. elegans IC50=0.46 μm; P. redivivus IC50=15.90 μm) and non-competitively by leuhistin (C. elegans IC50=3.00 μm; P. redivivus IC50=37.35 μm). The bioactive peptides adipokinetic hormone and substance P decrease the apparent aminopeptidase activities of each extract suggesting that the peptides compete with the Ala-pNA as substrates. With each extract, adipokinetic hormone appeared to be the more effective substrate. Digestion of adipokinetic hormone by C. elegans and P. redivivus extracts in the presence and absence of 1 mm amastatin produced distinct chromatographic profiles that suggest different digestion patterns for the two species. However, amastatin had clear effects on chromatographic profiles from each species indicating that an aminopeptidase is involved in the digestion of the peptide substrates. The data presented indicate that extracts of free-living nematodes are capable of metabolizing peptide hormones, and that this metabolism involves substrate-selective aminopeptidases.