Guéret Stéphanie M, Thavam Sasikala, Carbajo Rodrigo J, Potowski Marco, Larsson Niklas, Dahl Göran, Dellsén Anita, Grossmann Tom N, Plowright Alleyn T, Valeur Eric, Lemurell Malin, Waldmann Herbert
Department of Chemical Biology, AstraZeneca-Max Planck Institute Satellite Unit, Max-Planck-Institute of Molecular Physiology, 44227 Dortmund, Germany.
Medicinal Chemistry, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, 431 50 Gothenburg, Sweden.
J Am Chem Soc. 2020 Mar 11;142(10):4904-4915. doi: 10.1021/jacs.0c00269. Epub 2020 Mar 2.
"Hot loop" protein segments have variable structure and conformation and contribute crucially to protein-protein interactions. We describe a new hot loop mimicking modality, termed PepNats, in which natural product (NP)-inspired structures are incorporated as conformation-determining and -restricting structural elements into macrocyclic hot loop-derived peptides. Macrocyclic PepNats representing hot loops of inducible nitric oxide synthase (iNOS) and human agouti-related protein (AGRP) were synthesized on solid support employing macrocyclization by imine formation and subsequent stereoselective 1,3-dipolar cycloaddition as key steps. PepNats derived from the iNOS DINNN hot loop and the AGRP RFF hot spot sequence yielded novel and potent ligands of the SPRY domain-containing SOCS box protein 2 (SPSB2) that binds to iNOS, and selective ligands for AGRP-binding melanocortin (MC) receptors. NP-inspired fragment absolute configuration determines the conformation of the peptide part responsible for binding. These results demonstrate that combination of NP-inspired scaffolds with peptidic epitopes enables identification of novel hot loop mimics with conformationally constrained and biologically relevant structure.
“热环”蛋白片段具有可变的结构和构象，对蛋白质-蛋白质相互作用至关重要。我们描述了一种新的热环模拟方式，称为PepNats，其中受天然产物（NP）启发的结构作为构象决定和限制结构元件被纳入大环热环衍生肽中。代表诱导型一氧化氮合酶（iNOS）和人刺鼠相关蛋白（AGRP）热环的大环PepNats在固相载体上合成，采用亚胺形成大环化以及随后的立体选择性1,3-偶极环加成作为关键步骤。源自iNOS DINNN热环和AGRP RFF热点序列的PepNats产生了新型且有效的含SPRY结构域的SOCS盒蛋白2（SPSB2）配体，SPSB2可与iNOS结合，以及AGRP结合黑皮质素（MC）受体的选择性配体。受NP启发的片段绝对构型决定了负责结合的肽部分的构象。这些结果表明，将受NP启发的支架与肽表位相结合能够鉴定出具有构象受限且与生物学相关结构的新型热环模拟物。
