Kim I S, Lee K J
Department of Microbiology, College of Natural Science, Seoul National University, Korea.
Microbiology (Reading). 1995 Apr;141 ( Pt 4):1017-25. doi: 10.1099/13500872-141-4-1017.
Streptomyces exfoliatus SMF13 produced leupeptin, chymotrypsin-like protease (CTP), metalloprotease, and trypsin-like protease (TLP) extracellularly. The activity of TLP was specifically inhibited by leupeptin. Production of leupeptin was closely associated with growth but leupeptin was inactivated by leupeptin-inactivating protein (LIP) when growth reached the stationary phase in submerged cultures, or when aerial mycelia started to form on surface cultures. Autolysis of mycelia after the stationary phase in submerged cultures was apparently retarded by the addition of leupeptin; on surface cultures, aerial mycelium formation was clearly retarded by the addition of leupeptin. We propose that CTP participates primarily in utilization of a proteinaceous nitrogen source, that TLP functions as an essential enzyme involved in the metabolism of mycelial protein, that leupeptin inhibits the activity of TLP and that LIP inactivates leupeptin. The cascade of regulatory actions of the compounds, which are produced sequentially during mycelium development, may provide selective advantages in adverse culture conditions.
脱落链霉菌SMF13可在胞外产生亮抑酶肽、类胰凝乳蛋白酶（CTP）、金属蛋白酶和类胰蛋白酶（TLP）。亮抑酶肽可特异性抑制TLP的活性。亮抑酶肽的产生与生长密切相关，但在深层培养进入稳定期或在表面培养开始形成气生菌丝体时，亮抑酶肽会被亮抑酶肽失活蛋白（LIP）失活。在深层培养稳定期后添加亮抑酶肽可明显延缓菌丝体的自溶；在表面培养中，添加亮抑酶肽可明显抑制气生菌丝体的形成。我们认为CTP主要参与蛋白质氮源的利用，TLP作为一种必需酶参与菌丝体蛋白质的代谢，亮抑酶肽抑制TLP的活性，LIP使亮抑酶肽失活。在菌丝体发育过程中依次产生的这些化合物的级联调节作用，可能在不利的培养条件下提供选择优势。
