The Leishmania major leucyl-aminopeptidase (LAPLm), a member of the M17 family of proteases, is a potential drug target for treatment of leishmaniasis. To better characterize enzyme properties, recombinant LAPLm (rLAPLm) was expressed in Escherichia coli. A LAPLm gene was designed, codon-optimized for expression in E. coli, synthesized and cloned into the pET-15b vector. Production of rLAPLm in E. coli Lemo21(DE3), induced for 4 h at 37 °C with 400 μM IPTG and 250 μM l-rhamnose, yielded insoluble enzyme with a low proportion of soluble and active protein, only detected by an anti-His antibody-based western-blot. rLAPLm was purified in a single step by immobilized metal ion affinity chromatography. rLAPLm was obtained with a purity of ~10% and a volumetric yield of 2.5 mg per liter, sufficient for further characterization. The aminopeptidase exhibits optimal activity at pH 7.0 and a substrate preference for Leu-p-nitroanilide (appKM = 30 μM, appkcat = 14.7 s-1). Optimal temperature is 50 °C, and the enzyme is insensitive to 4 mM Co2+, Mg2+, Ca2+ and Ba2+. However, rLAPLm was activated by Zn2+, Mn2+ and Cd2+ but is insensitive towards the protease inhibitors PMSF, TLCK, E-64 and pepstatin A, being inhibited by EDTA and bestatin. Bestatin is a potent, non-competitive inhibitor of the enzyme with a Ki value of 994 nM. We suggest that rLAPLm is a suitable target for inhibitor identification.

• MeSH
• aminopeptidasy * biosyntéza   chemie   genetika   izolace a purifikace   MeSH
• Escherichia coli * genetika   metabolismus   MeSH
• kinetika MeSH
• Leishmania major * enzymologie   genetika   MeSH
• protozoální proteiny * biosyntéza   chemie   genetika   izolace a purifikace   MeSH
• rekombinantní proteiny biosyntéza   chemie   genetika   izolace a purifikace   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Leucyl aminopeptidases (LAPs) are involved in multiple cellular functions, which, in the case of infectious diseases, includes participation in the pathogen-host cell interface and pathogenesis. Thus, LAPs are considered good candidate drug targets, and the major M17-LAP from Trypanosoma cruzi (LAPTc) in particular is a promising target for Chagas disease. To exploit LAPTc as a potential target, it is essential to develop potent and selective inhibitors. To achieve this, we report a high-throughput screening method for LAPTc. Two methods were developed and optimized: a Leu-7-amido-4-methylcoumarin-based fluorogenic assay and a RapidFire mass spectrometry (RapidFire MS)-based assay using the LSTVIVR peptide as substrate. Compared with a fluorescence assay, the major advantages of the RapidFire MS assay are a greater signal-to-noise ratio as well as decreased consumption of enzyme. RapidFire MS was validated with the broad-spectrum LAP inhibitors bestatin (IC50 = 0.35 μM) and arphamenine A (IC50 = 15.75 μM). We suggest that RapidFire MS is highly suitable for screening for specific LAPTc inhibitors.

• MeSH
• Chagasova nemoc diagnóza   enzymologie   parazitologie   MeSH
• hmotnostní spektrometrie MeSH
• kinetika MeSH
• leucylaminopeptidasa genetika   izolace a purifikace   MeSH
• lidé MeSH
• rychlé screeningové testy * MeSH
• sekvence aminokyselin genetika   MeSH
• substrátová specifita MeSH
• Trypanosoma cruzi enzymologie   izolace a purifikace   patogenita   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH