title: Design of proteolytically stable RI-anchoring disruptor peptidomimetics for in vivo studies of anchored type I protein kinase A-mediated signalling.
abstract: We have reported previously the design of a RIAD (RI-anchoring disruptor) peptide that specifically displaces PKA (protein kinase A) type I from the AKAP (A-kinase-anchoring protein) ezrin, which is present in the immunological synapse of T-cells. This increases immune reactivity by reducing the threshold for activation and may prove a feasible approach for improving immune function in patients with cAMP-mediated T-cell dysfunction. However, the use of RIAD in biological systems is restricted by its susceptibility to enzymatic cleavage and, consequently, its short half-life in presence of the ubiquitous serum peptidases. In the present study, carefully selected non-natural amino acids were employed in the design of RIAD analogues with improved stability. The resulting peptidomimetics demonstrated up to 50-fold increased half-lives in serum compared with RIAD, while maintaining similar or improved specificity and potency with respect to disruption of PKA type I-AKAP interactions.
authors.affiliation: Biotechnology Centre of Oslo and Centre for Molecular Medicine Norway, Nordic EMBL Partnership, University of Oslo, N-0317 Oslo, Norway.
authors.forename: Eirik A
authors.initials: EA
authors.lastname: Torheim
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Jarnaess
authors.forename: Birgitte
authors.initials: B
authors.lastname: Lygren
authors.forename: Kjetil
authors.initials: K
authors.lastname: Taskén
mesh_terms: D054758:A Kinase Anchor Proteins / Q000378:metabolism*; D000818:Animals; D000081247:CSK Tyrosine-Protein Kinase; D002417:Cattle; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D000242:Cyclic AMP / Q000378:metabolism; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism; D051379:Mice; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D019061:src-Family Kinases
chemical_list: D054758:A Kinase Anchor Proteins; D007376:Interleukin-2; D010455:Peptides; D000242:Cyclic AMP; D011505:Protein-Tyrosine Kinases; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases; C000631346:CSK protein, human