Potential Applicability of Chymotrypsin-Susceptible Microcin J25 Derivatives to Food Preservation
Potential Applicability of Chymotrypsin-Susceptible Microcin J25 Derivatives to Food Preservation
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DOI：
10.1128/aem.01070-09
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发表时间：
2009-09-01
影响因子：
4.4
通讯作者：
Vincent, Paula A.
中科院分区：
文献类型：
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作者：
Fernanda Pomares, Maria;Salomon, Raul A.;Vincent, Paula A.
微球素J25(MccJ25)是一种由核糖体合成的21个残基的套索多肽抗生素。MccJ25对沙门氏菌、志贺氏菌和大肠埃希氏菌等食源性致病病原体具有活性，包括大肠杆菌O157：H7和非O157菌株。MccJ25对胃和肠道内容物中存在的蛋白水解酶具有高度的抵抗力。因此，MccJ25会在胃肠道中保持活跃，影响正常的肠道微生物区系，这限制了MccJ25作为食品防腐剂的潜在用途。在本文中，我们描述了一种凝乳酶敏感的MccJ25衍生物，它将Gly(12)突变为Tyr，几乎保持了全部的抗生素活性，并有效地抑制了致病性肠炎沙门氏菌Newport和大肠杆菌O157：H7在脱脂牛奶和蛋黄中的生长。然而，与野生型MccJ25不同的是，MccJ25(G12Y)变异体在体外和体内都被消化酶灭活。据我们所知，我们的结果是对微球蛋白进行合理修饰的第一个例子，目的是增加其在食品保鲜中的潜在用途。
Microcin J25 (MccJ25) is a 21-residue ribosomally synthesized lariat peptide antibiotic. MccJ25 is active against such food-borne disease-causing pathogens as Salmonella spp., Shigella spp., and Escherichia coli, including E. coli O157:H7 and non-O157 strains. MccJ25 is highly resistant to digestion by proteolytic enzymes present in the stomach and intestinal contents. MccJ25 would therefore remain active in the gastrointestinal tract, affecting normal intestinal microbiota, and this limits the potential use of MccJ25 as a food preservative. In the present paper, we describe a chymotrypsin-susceptible MccJ25 derivative with a mutation of Gly(12) to Tyr that retained almost full antibiotic activity and efficiently inhibited the growth of pathogenic Salmonella enterica serovar Newport and Escherichia coli O157: H7 in skim milk and egg yolk. However, unlike the wild-type MccJ25, the MccJ25(G12Y) variant was inactivated by digestive enzymes both in vitro and in vivo. To our knowledge, our results represent the first example of a rational modification of a microcin aimed at increasing its potential use in food preservation.