TY - JOUR

T1 - Heat Shock Proteins Revisited:

T2 - Using a Mutasynthetically Generated Reblastatin Library to Compare the Inhibition of Human and Leishmania Hsp90s

AU - Mohammadi-Ostad-Kalayeh, Sona

AU - Stahl, Frank

AU - Scheper, Thomas

AU - Kock, Klaus

AU - Herrmann, Christian

AU - Heleno Batista, Fernanda Aparecida

AU - Borges, Júlio César

AU - Sasse, Florenz

AU - Eichner, Simone

AU - Ongouta, Jekaterina

AU - Zeilinger, Carsten

AU - Kirschning, Andreas

N1 - Funding information: This work was supported by the Deutsche Forschungsgemein-schaft (DFG, grant Ki 13-1). J.C.B. thanks the S¼o Paulo Research Foundation (FAPESP 2012/50161-8 and 2014/07206-6) and the Brazilian Council for Scientific and Technological Development (CNPq 303129/2015-8 and 471415/2013-8) for financial support.

PY - 2018/3/25

Y1 - 2018/3/25

N2 - Thirteen new reblastatin derivatives, with alkynyl, amino and fluoro substituents on the aromatic ring, were prepared by a chemo-biosynthetic approach using an AHBA(−) mutant strain of Streptomyces hygroscopicus, the geldanamycin producer. The inhibitory potencies of these mutaproducts and of an extended library of natural products and derivatives were probed with purified heat shock proteins (Hsps), obtained from Leishmania braziliensis (LbHsp90) as well as from human sources (HsHsp90). We determined the activities of potential inhibitors by means of a displacement assay in which fluorescence-labelled ATP competes for the ATP binding sites of Hsps in the presence of the inhibitor in question. The results were compared with those of cell-based assays and, in selected cases, of isothermal titration calorimetry (ITC) measurements. In essence, reblastatin derivatives are also able to bind effectively to the ATP-binding site of LbHsp90, and for selected derivatives, moderate differences in binding to LbHsp90 and HsHsp90 were encountered. This work demonstrates that parasitic heat shock proteins can be developed as potential pharmaceutical targets.

AB - Thirteen new reblastatin derivatives, with alkynyl, amino and fluoro substituents on the aromatic ring, were prepared by a chemo-biosynthetic approach using an AHBA(−) mutant strain of Streptomyces hygroscopicus, the geldanamycin producer. The inhibitory potencies of these mutaproducts and of an extended library of natural products and derivatives were probed with purified heat shock proteins (Hsps), obtained from Leishmania braziliensis (LbHsp90) as well as from human sources (HsHsp90). We determined the activities of potential inhibitors by means of a displacement assay in which fluorescence-labelled ATP competes for the ATP binding sites of Hsps in the presence of the inhibitor in question. The results were compared with those of cell-based assays and, in selected cases, of isothermal titration calorimetry (ITC) measurements. In essence, reblastatin derivatives are also able to bind effectively to the ATP-binding site of LbHsp90, and for selected derivatives, moderate differences in binding to LbHsp90 and HsHsp90 were encountered. This work demonstrates that parasitic heat shock proteins can be developed as potential pharmaceutical targets.

KW - geldanamycin

KW - heat shock proteins

KW - inhibitors

KW - Leishmania

KW - microarrays

UR - http://www.scopus.com/inward/record.url?scp=85042103305&partnerID=8YFLogxK

U2 - 10.1002/cbic.201700616

DO - 10.1002/cbic.201700616

M3 - Article

C2 - 29265716

AN - SCOPUS:85042103305

VL - 19

SP - 562

EP - 574

JO - CHEMBIOCHEM

JF - CHEMBIOCHEM

SN - 1439-4227

IS - 6

ER -