Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Institute of Medical Microbiology and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China.
Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201203, China.
Microbiology (Reading). 2010 Oct;156(Pt 10):3194-3202. doi: 10.1099/mic.0.038174-0. Epub 2010 Jul 23.
The emergence of multi-drug-resistant strains of Staphylococcus epidermidis emphasizes the need to develop new antibiotics. The unique and essential role of the peptide deformylase (PDF) in catalysing the removal of the N-terminal formyl group from newly synthesized polypeptides in eubacteria makes it an attractive antibacterial drug target. In the present study, both deformylase homologues from S. epidermidis (SePDF-1 and SePDF-2) were cloned and expressed, and their enzymic activities were characterized. Co(2+)-substituted SePDF-1 exhibited much higher enzymic activity (k(cat)/K(m) 6.3 × 10(4) M(-1) s(-1)) than those of Ni(2+)- and Zn(2+)-substituted SePDF-1, and SePDF-1 showed much weaker binding ability towards Ni(2+) than towards Co(2+) and Zn(2+), which is different from PDF in Staphylococcus aureus (SaPDF), although they share 80 % amino-acid sequence identity. The determined crystal structure of SePDF-1 was similar to that of (SaPDF), except for differences in the metal-binding sites. The other deformylase homologue, SePDF-2, was shown to have no peptide deformylase activity; the function of SePDF-2 needs to be further investigated.
表皮葡萄球菌中多药耐药菌株的出现强调了开发新抗生素的必要性。肽脱甲酰基酶（PDF）在催化真细菌中新合成多肽的 N-末端甲酰基去除方面具有独特而必需的作用，使其成为有吸引力的抗菌药物靶标。在本研究中，我们克隆和表达了表皮葡萄球菌中的两种 PDF 同工酶（SePDF-1 和 SePDF-2），并对其酶活性进行了表征。与 Ni2+和 Zn2+取代的 SePDF-1 相比，Co2+取代的 SePDF-1 表现出更高的酶活性（kcat/Km 为 6.3×104 M-1 s-1），并且 SePDF-1 对 Ni2+的结合能力比 Co2+和 Zn2+弱，这与金黄色葡萄球菌中的 PDF 不同，尽管它们具有 80%的氨基酸序列同一性。确定的 SePDF-1 晶体结构与（SaPDF）相似，只是金属结合位点不同。另一种同工酶 SePDF-2 没有肽脱甲酰基酶活性；需要进一步研究 SePDF-2 的功能。
