Comment on « N-terminal Protein Tail Acts as Aggregation Protective Entropic Bristles : The SUMO Case »

We provide a robust protocol for the far-UV CD analysis of SUMO-2 protein and SUMO-2 core domain as well as all the data as supplementary files for those interested by the study of SUMO protein conformation.These analyses were performed after having read the report published in 2014 by Grana-Montes, R. et al. (Grana-Montes, R.; Marinelli, P.; Reverter, D.; Ventura, S., N-terminal protein tails act as aggregation protective entropic bristles: the SUMO case. Biomacromolecules 2014, 15 (4), 1194-203. DOI: 10.1021/bm401776z).<br /

Comment on “N-terminal Protein Tail Acts as Aggregation Protective Entropic Bristles: The SUMO Case”

International audienceSUMO-2 protein, SUMO-2 core domain, and the tail peptide corresponding to the first 14 residues were produced by chemical synthesis, and their secondary structures were analyzed by circular dichroism. The CD spectra of SUMO-2 and SUMO-2 core domain show distinct features and α-helical contents. In particular, the presence of the disordered tail in SUMO-2 lowers the α-helical content of the protein compared with SUMO-2 core domain and also explains the shift in the position of the minimum around 208 nm

Total Chemical Synthesis of All SUMO-2/3 Dimer Combinations

International audienceOne hallmark of protein chemical synthesis is its capacity to access proteins that living systems can hardly produce. This is typically the case for proteins harboring post-translational modifications such as ubiquitin or ubiquitin-like modifiers. Various methods have been developed for accessing polyubiquitin conjugates by semi- or total synthesis. Comparatively, the preparation of small-ubiquitin-like modifier (SUMO) conjugates, and more particularly of polySUMO scaffolds, is much less developed. We describe hereinafter a synthetic strategy for accessing all SUMO-2/3 dimer combinations

The Problem of Aspartimide Formation During Protein Chemical Synthesis Using SEA-Mediated Ligation

Aspartimide formation often complicates the solid phase synthesis of peptides. Much less discussed is the potential occurrence of this side-reaction during the coupling of peptide segments using chemoselective peptide bond forming reactions such as the native chemical ligation and extended methods. Here we describe how to manage this problem using bis(2-sulfenylethyl)amido (SEA)-mediated ligation and SUMO-2/SUMO-3 as protein targets.<br /

Expression and purification in high yield of a functionally active recombinant human Type I inositol(1,4,5)P3 5-phosphatase.

Inositol polyphosphates are the most widespread second messenger molecules in eukaryotic cells. Human Type I inositol 1,4,5-triphosphate (Ins(1,4,5)P(3)) 5-phosphatase removes the D-5 position phosphate from soluble Ins(1,4,5)P(3,) a key event in cell signaling particularly in Ca(2+) homeostasis. In this study, the cDNA encoding human Type I Ins(1,4,5)P(3) 5-phosphatase was subcloned into a modified pMAL expression vector. This plasmid produces a recombinant protein in fusion with affinity tags located at its N-terminus, consisting in a maltose binding protein (MPB) and an octa-histidine stretch. The construction was transformed into Escherichia coli BL21 (DE3) expression strain. This dual tag strategy allows the purification of milligrams of highly purified protein. The recombinant human Type I Ins(1,4,5)P(3) 5-phosphatase is active and can thus be used for functional and structural studies.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

The Role of the Conserved SUMO-2/3 Cysteine Residue on Domain Structure Investigated Using Protein Chemical Synthesis

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The peptidyl-prolyl isomerase and chaperone Par27 of Bordetella pertussis as the prototype for a new group of parvulins.

Proteins that pass through the periplasm in an unfolded state are highly sensitive to proteolysis and aggregation and, therefore, often require protection by chaperone-like proteins. The periplasm of Gram-negative bacteria is well equipped with ATP-independent chaperones and folding catalysts, including peptidyl-prolyl isomerases (PPIases). The filamentous hemagglutinin of Bordetella pertussis, which is secreted by the two-partner secretion pathway, crosses the periplasm in an unfolded conformation. By affinity chromatography, we identified a new periplasmic PPIase of the parvulin family, Par27, which binds to an unfolded filamentous hemagglutinin fragment. Par27 differs from previously characterized bacterial and eukaryotic parvulins. Its central parvulin-like domain is flanked by atypical N- and C-terminal extensions that are found in a number of putative PPIases present mostly in beta proteobacteria. Par27 displays both PPIase and chaperone activities in vitro. In vivo, Par27 might function as a general periplasmic chaperone in B. pertussis

Solution structure of the N-terminal transactivation domain of ERM modified by SUMO-1.

ERM is a member of the PEA3 group of the Ets transcription factor family that plays important roles in development and tumorigenesis. The PEA3s share an N-terminal transactivation domain (TADn) whose activity is inhibited by small ubiquitin-like modifier (SUMO). However, the consequences of sumoylation and its underlying molecular mechanism remain unclear. The domain structure of ERM TADn alone or modified by SUMO-1 was analyzed using small-angle X-ray scattering (SAXS). Low resolution shapes determined ab initio from the scattering data indicated an elongated shape and an unstructured conformation of TADn in solution. Covalent attachment of SUMO-1 does not perturb the structure of TADn as indicated by the linear arrangement of the SUMO moiety with respect to TADn. Thus, ERM belongs to the growing family of proteins that contain intrinsically unstructured regions. The flexible nature of TADn may be instrumental for ERM recognition and binding to diverse molecular partners.Journal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe