title: Active Site Mapping of an Aspartic Protease by Multiple Fragment Crystal Structures: Versatile Warheads To Address a Catalytic Dyad.
abstract: Crystallography is frequently used as follow-up method to validate hits identified by biophysical screening cascades. The capacity of crystallography to directly screen fragment libraries is often underestimated, due to its supposed low-throughput and need for high-quality crystals. We applied crystallographic fragment screening to map the protein-binding site of the aspartic protease endothiapepsin by individual soaking experiments. Here, we report on 41 fragments binding to the catalytic dyad and adjacent specificity pockets. The analysis identifies already known warheads but also reveals hydrazide, pyrazole, or carboxylic acid fragments as novel functional groups binding to the dyad. A remarkable swapping of the S1 and S1' pocket between structurally related fragments is explained by either steric demand, required displacement of a well-bound water molecule, or changes of trigonal-planar to tetrahedral geometry of an oxygen functional group in a side chain. Some warheads simultaneously occupying both S1 and S1' are promising starting points for fragment-growing strategies.
authors.affiliation: Department of Pharmaceutical Chemistry, Philipps University Marburg , Marbacher Weg 6, 35032 Marburg, Germany.
authors.forename: Nedyalka
authors.initials: N
authors.lastname: Radeva
authors.affiliation: Department of Pharmaceutical Chemistry, Philipps University Marburg , Marbacher Weg 6, 35032 Marburg, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Schiebel
authors.affiliation: Department of Pharmaceutical Chemistry, Philipps University Marburg , Marbacher Weg 6, 35032 Marburg, Germany.
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Pharmaceutical Chemistry, Philipps University Marburg , Marbacher Weg 6, 35032 Marburg, Germany.
authors.forename: Stefan G
authors.initials: SG
authors.lastname: Krimmer
authors.affiliation: Department of Pharmaceutical Chemistry, Philipps University Marburg , Marbacher Weg 6, 35032 Marburg, Germany.
authors.forename: Kan
authors.initials: K
authors.lastname: Fu
authors.affiliation: Department of Pharmaceutical Chemistry, Philipps University Marburg , Marbacher Weg 6, 35032 Marburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Stieler
authors.affiliation: Department of Pharmaceutical Chemistry, Philipps University Marburg , Marbacher Weg 6, 35032 Marburg, Germany.
authors.forename: Frederik R
authors.initials: FR
authors.lastname: Ehrmann
authors.affiliation: Department of Pharmaceutical Chemistry, Philipps University Marburg , Marbacher Weg 6, 35032 Marburg, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Metz
authors.affiliation: Department of Pharmaceutical Chemistry, Philipps University Marburg , Marbacher Weg 6, 35032 Marburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Rickmeyer
authors.affiliation: Department of Pharmaceutical Chemistry, Philipps University Marburg , Marbacher Weg 6, 35032 Marburg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Betz
authors.affiliation: Department of Pharmaceutical Chemistry, Philipps University Marburg , Marbacher Weg 6, 35032 Marburg, Germany.
authors.forename: Johan
authors.initials: J
authors.lastname: Winquist
authors.affiliation: Department of Pharmaceutical Chemistry, Philipps University Marburg , Marbacher Weg 6, 35032 Marburg, Germany.
authors.forename: Ah Young
authors.initials: AY
authors.lastname: Park
authors.affiliation: Department of Pharmaceutical Chemistry, Philipps University Marburg , Marbacher Weg 6, 35032 Marburg, Germany.|Helmholtz-Zentrum Berlin für Materialien und Energie, Macromolecular Crystallography (HZB-MX), Albert-Einstein-Strasse 15, 12489 Berlin, Germany.
authors.forename: Franziska U
authors.initials: FU
authors.lastname: Huschmann
authors.affiliation: Helmholtz-Zentrum Berlin für Materialien und Energie, Macromolecular Crystallography (HZB-MX), Albert-Einstein-Strasse 15, 12489 Berlin, Germany.
authors.forename: Manfred S
authors.initials: MS
authors.lastname: Weiss
authors.affiliation: Helmholtz-Zentrum Berlin für Materialien und Energie, Macromolecular Crystallography (HZB-MX), Albert-Einstein-Strasse 15, 12489 Berlin, Germany.|MAX IV Laboratory, Lund University , Fotongatan 2, 225 94 Lund, Sweden.
authors.forename: Uwe
authors.initials: U
authors.lastname: Mueller
authors.affiliation: Department of Pharmaceutical Chemistry, Philipps University Marburg , Marbacher Weg 6, 35032 Marburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Heine
authors.affiliation: Department of Pharmaceutical Chemistry, Philipps University Marburg , Marbacher Weg 6, 35032 Marburg, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Klebe
mesh_terms: D057055:Aspartic Acid Proteases / Q000737:chemistry* / Q000378:metabolism*; D055162:Biocatalysis; D002151:Calorimetry; D002264:Carboxylic Acids / Q000737:chemistry / Q000378:metabolism*; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D006834:Hydrazines / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D011720:Pyrazoles / Q000737:chemistry / Q000378:metabolism*
chemical_list: D002264:Carboxylic Acids; D006834:Hydrazines; D011720:Pyrazoles; C031280:pyrazole; D057055:Aspartic Acid Proteases