Shibata Nobuyuki, Okanuma Noriko, Hirai Kanako, Arikawa Kumiko, Kimura Mayumi, Okawa Yoshio
Second Department of Hygienic Chemistry, Tohoku Pharmaceutical University, Sendai, Miyagi, Japan.
FEMS Microbiol Lett. 2006 Mar;256(1):137-44. doi: 10.1111/j.1574-6968.2006.00106.x.
Lipophilic Malassezia species may induce catheter-associated sepsis in premature neonates and immunocompromised patients receiving parenteral lipid emulsions. To assess the participation of lipolytic enzymes in the pathogenesis of this yeast, we cloned a gene encoding the enzyme. A lipolytic enzyme in the culture supernatant of Malassezia pachydermatis was purified 210-fold to homogeneity. The enzyme showed high esterase activity toward p-nitrophenyl octanoate. The cDNA encoding the enzyme was cloned using a degenerate oligonucleotide primer constructed from the N-terminal amino acid sequence. The cDNA consisted of 1582 bp, including an open reading frame encoding 470 amino acids. The first 19 amino acids and the following 13 amino-acid sequence were predicted to be the signal peptides for secretion and prosequence, respectively. The predicted molecular mass of the 438-amino acid mature protein was 48 kDa. Analysis of the deduced amino acid sequence revealed that it contains the consensus motif (Gly-X-Ser-X-Gly), which is conserved among lipolytic enzymes. Homology investigations showed that the enzyme has similarities principally with 11 lipases produced by Candida albicans (29-34% identity) and some other yeast lipases.
亲脂性马拉色菌属可能在接受肠外脂肪乳剂的早产儿和免疫功能低下患者中引发与导管相关的败血症。为了评估脂解酶在这种酵母菌发病机制中的作用，我们克隆了编码该酶的基因。从厚皮马拉色菌培养上清液中纯化出一种脂解酶，纯化倍数达210倍，达到了均一性。该酶对对硝基苯基辛酸酯显示出高酯酶活性。利用根据N端氨基酸序列构建的简并寡核苷酸引物克隆了编码该酶的cDNA。该cDNA由1582个碱基对组成，包括一个编码470个氨基酸的开放阅读框。预计前19个氨基酸和随后的13个氨基酸序列分别为分泌信号肽和前导序列。预测的438个氨基酸成熟蛋白的分子量为48 kDa。对推导的氨基酸序列分析表明，它含有脂解酶中保守的共有基序（甘氨酸- X -丝氨酸- X -甘氨酸）。同源性研究表明，该酶主要与白色念珠菌产生的11种脂肪酶（同一性为29 - 34%）和其他一些酵母脂肪酶具有相似性。
