Cryptococcosis is an invasive infection that accounts for 15% of AIDS-related fatalities. Still, treating cryptococcosis remains a significant challenge due to the poor availability of effective antifungal therapies and emergence of drug resistance. Interestingly, protease inhibitor components of antiretroviral therapy regimens have shown some clinical benefits in these opportunistic infections. We investigated Major aspartyl peptidase 1 (May1), a secreted Cryptococcus neoformans protease, as a possible target for the development of drugs that act against both fungal and retroviral aspartyl proteases. Here, we describe the biochemical characterization of May1, present its high-resolution X-ray structure, and provide its substrate specificity analysis. Through combinatorial screening of 11,520 compounds, we identified a potent inhibitor of May1 and HIV protease. This dual-specificity inhibitor exhibits antifungal activity in yeast culture, low cytotoxicity, and low off-target activity against host proteases and could thus serve as a lead compound for further development of May1 and HIV protease inhibitors.

• MeSH
• antifungální látky chemie   metabolismus   farmakologie   MeSH
• aspartátové proteasy antagonisté a inhibitory   genetika   metabolismus   MeSH
• Cryptococcus neoformans enzymologie   MeSH
• fungální proteiny antagonisté a inhibitory   genetika   metabolismus   MeSH
• HIV-proteasa chemie   metabolismus   MeSH
• HIV enzymologie   MeSH
• houby účinky léků   MeSH
• katalytická doména MeSH
• krystalografie rentgenová MeSH
• preklinické hodnocení léčiv MeSH
• rekombinantní proteiny biosyntéza   chemie   izolace a purifikace   MeSH
• simulace molekulární dynamiky MeSH
• substrátová specifita MeSH
• vazebná místa MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• antifungální látky MeSH
• aspartátové proteasy MeSH
• fungální proteiny MeSH
• HIV-proteasa MeSH
• rekombinantní proteiny MeSH

All retroviral proteases belong to the family of aspartic proteases. They are active as homodimers, each unit contributing one catalytic aspartate to the active site dyad. An important feature of all aspartic proteases is a conserved complex scaffold of hydrogen bonds supporting the active site, called the "fireman's grip," which involves the hydroxyl groups of two threonine (serine) residues in the active site Asp-Thr(Ser)-Gly triplets. It was shown previously that the fireman's grip is indispensable for the dimer stability of HIV protease. The retroviral proteases harboring Ser in their active site triplet are less active and, under natural conditions, are expressed in higher enzyme/substrate ratio than those having Asp-Thr-Gly triplet. To analyze whether this observation can be attributed to the different influence of Thr or Ser on dimerization, we prepared two pairs of the wild-type and mutant proteases from HIV and myeloblastosis-associated virus harboring either Ser or Thr in their Asp-Thr(Ser)-Gly triplet. The equilibrium dimerization constants differed by an order of magnitude within the relevant pairs. The proteases with Thr in their active site triplets were found to be approximately 10 times more thermodynamically stable. The dimer association contributes to this difference more than does the dissociation. We propose that the fireman's grip might be important in the initial phases of dimer formation to help properly orientate the two subunits of a retroviral protease. The methyl group of threonine might contribute significantly to fixing such an intermediate conformation.

• MeSH
• algoritmy MeSH
• aspartátové endopeptidasy chemie   genetika   metabolismus   MeSH
• bodová mutace genetika   MeSH
• dimerizace MeSH
• fluorescenční barviva metabolismus   MeSH
• HIV-proteasa chemie   genetika   metabolismus   MeSH
• kinetika MeSH
• lidé MeSH
• molekulární modely MeSH
• rekombinantní proteiny chemie   genetika   metabolismus   MeSH
• Retroviridae - proteiny chemie   genetika   metabolismus   MeSH
• serin chemie   genetika   MeSH
• stabilita enzymů genetika   MeSH
• substrátová specifita MeSH
• threonin chemie   genetika   MeSH
• vazebná místa genetika   MeSH
• vodíková vazba MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• aspartátové endopeptidasy MeSH
• fluorescenční barviva MeSH
• HIV-proteasa MeSH
• protease p15 MeSH Prohlížeč
• rekombinantní proteiny MeSH
• Retroviridae - proteiny MeSH
• serin MeSH
• threonin MeSH