Rousset A, Nguyen-Distèche M, Minck R, Ghuysen J M
J Bacteriol. 1982 Dec;152(3):1042-8. doi: 10.1128/jb.152.3.1042-1048.1982.
The originally penicillin-induced, wall-less stable L-forms of Proteus vulgaris P18, isolated by Tulasne in 1949 and since then cultured in he absence of penicillin, have kept the ability to synthesize the seven penicillin-binding proteins and the various DD- and LD-peptidase activities found in the parental bacteria and known to be involved in wall peptidoglycan metabolism. The stable L-forms, however, secrete during growth both the highly penicillin-sensitive, DD-carboxy-peptidase-transpeptidase penicillin-binding protein PBP4 (which in normal bacteria is relatively loosely bound to the plasma membrane) and the penicillin-insensitive LD-carboxypeptidase (which in normal bacteria is located in the periplasmic region).
1949年图拉斯内分离出的普通变形杆菌P18最初由青霉素诱导形成的无壁稳定L型，自那时起在无青霉素的情况下培养，它仍保留合成七种青霉素结合蛋白的能力，以及在亲代细菌中发现的、已知参与细胞壁肽聚糖代谢的各种DD-和LD-肽酶活性。然而，稳定的L型在生长过程中会分泌高度青霉素敏感的DD-羧肽酶-转肽酶青霉素结合蛋白PBP4（在正常细菌中它相对松散地结合在质膜上）和青霉素不敏感的LD-羧肽酶（在正常细菌中位于周质区域）。
