title: Design of new enzyme stabilizers inspired by glycosides of hyperthermophilic microorganisms.
abstract: In response to stressful conditions like supra-optimal salinity in the growth medium or temperature, many microorganisms accumulate low-molecular-mass organic compounds known as compatible solutes. In contrast with mesophiles that accumulate neutral or zwitterionic compounds, the solutes of hyperthermophiles are typically negatively charged. (2R)-2-(alpha-D-Mannopyranosyl)glycerate (herein abbreviated as mannosylglycerate) is one of the most widespread solutes among thermophilic and hyperthermophilic prokaryotes. In this work, several molecules chemically related to mannosylglycerate were synthesized, namely (2S)-2-(1-O-alpha-D-mannopyranosyl)propionate, 2-(1-O-alpha-D-mannopyranosyl)acetate, (2R)-2-(1-O-alpha-D-glucopyranosyl)glycerate and 1-O-(2-glyceryl)-alpha-D-mannopyranoside. The effectiveness of the newly synthesized compounds for the protection of model enzymes against heat-induced denaturation, aggregation and inactivation was evaluated, using differential scanning calorimetry, light scattering and measurements of residual activity. For comparison, the protection induced by natural compatible solutes, either neutral (e.g., trehalose, glycerol, ectoine) or negatively charged (di-myo-inositol-1,3'-phosphate and diglycerol phosphate), was assessed. Phosphate, sulfate, acetate and KCl were also included in the assays to rank the solutes and new compounds in the Hofmeister series. The data demonstrate the superiority of charged organic solutes as thermo-stabilizers of enzymes and strongly support the view that the extent of protein stabilization rendered by those solutes depends clearly on the specific solute/enzyme examined. The relevance of these findings to our knowledge on the mode of action of charged solutes is discussed.
authors.affiliation: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Biology Division, Rua da Quinta Grande 6, Apartado 127, 2780-156 Oeiras, Portugal.
authors.forename: Tiago Q
authors.initials: TQ
authors.lastname: Faria
authors.forename: Ana
authors.initials: A
authors.lastname: Mingote
authors.forename: Filipa
authors.initials: F
authors.lastname: Siopa
authors.forename: Rita
authors.initials: R
authors.lastname: Ventura
authors.forename: Christopher
authors.initials: C
authors.lastname: Maycock
authors.forename: Helena
authors.initials: H
authors.lastname: Santos
mesh_terms: D000818:Animals; D055162:Biocatalysis / Q000187:drug effects; D002152:Calorimetry, Differential Scanning; D015195:Drug Design; D004795:Enzyme Stability / Q000187:drug effects; D005988:Glyceric Acids / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D006027:Glycosides / Q000737:chemistry*; D006358:Hot Temperature; D007770:L-Lactate Dehydrogenase / Q000737:chemistry / Q000378:metabolism; D008027:Light; D008291:Malate Dehydrogenase / Q000737:chemistry / Q000378:metabolism; D008358:Mannose / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D008827:Microbiological Phenomena; D008836:Micrococcal Nuclease / Q000737:chemistry / Q000378:metabolism; D009113:Muramidase / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D011489:Protein Denaturation / Q000187:drug effects; D011817:Rabbits; D013816:Thermodynamics
chemical_list: D005988:Glyceric Acids; D006027:Glycosides; C402688:mannosylglycerate; D007770:L-Lactate Dehydrogenase; D008291:Malate Dehydrogenase; D008836:Micrococcal Nuclease; D009113:Muramidase; D008358:Mannose