Crystal Structure of the B Subunit of Escherichia coli Heat-labile Enterotoxin Carrying Peptides with Anti-herpes Simplex Virus Type 1 Activity

Matković‐Čalogović, Dubravka; Loregian, Arianna; D’Acunto, Maria Rosa; Battistutta, Roberto; Tossi, Alessandro; Palù, Giorgio; Zanotti, Giuseppe

doi:10.1016/s0021-9258(19)87394-5

Cited by 10 publications

(2 citation statements)

References 36 publications

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“…Proteins showcasing this type of fold have the ability to establish protein-DNA, -RNA or -protein interactions and so are usually involved in a number of cellular processes such as DNA replication and repair, and activation of the DNA-damage checkpoint pathways [85] , [86] , [87] . DsbA substrates found to have this type of fold include secreted toxins such as CtxB from V. cholerae [87] , [88] , [89] , EltB from E. coli [87] , [90] , and the N-terminal domain of S2 subunit from B. pertussis [91] , [92] .…”

Section: Structural Variability Of Dsba Substratesmentioning

confidence: 99%

Structural bioinformatic analysis of DsbA proteins and their pathogenicity associated substrates

Santos-Martin

Wang

Subedi

et al. 2021

Computational and Structural Biotechnology Journal

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Section: Structural Variability Of Dsba Substratesmentioning

confidence: 99%

Structural bioinformatic analysis of DsbA proteins and their pathogenicity associated substrates

Santos-Martin

Wang

Subedi

et al. 2021

Computational and Structural Biotechnology Journal

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“…Further studies using multidimensional nuclear magnetic resonance (NMR) confirmed that the 36-residue peptide in aqueous solution contains partially ordered N-and C-terminal R-helices separated by a less ordered region (14). The 3 Å resolution of the molecular structure of the EtxB-Pol peptide fusion indicated that the 27-mer, when attached to the C-terminus of EtxB, is likely disordered (15). However, none of these studies has investigated whether Pol peptide undergoes a structural change upon acidification which could allow interaction with the lipid membrane and subsequent translocation.…”

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confidence: 97%

pH-Dependent Conformational Changes and Topology of a Herpesvirus Translocating Peptide in a Membrane-Mimetic Environment

et al. 2004

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Pol peptide, an oligopeptide corresponding to the 27 C-terminal amino acids of DNA polymerase from herpes simplex virus type 1, has recently been suggested to translocate from endosomal compartments into the cytosol after being intracellularly delivered via a protein carrier. While an acidic environment was thought to be important for Pol peptide membrane translocation, the mechanism of translocation remains unclear. To investigate the influence of an acidic environment on the conformational properties of the peptide and on its propensity to interact with lipid bilayers, we characterized the structure of Pol peptide at different pH values by both circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy. The influence of detergent micelles, which mimic biological lipid membranes, on the peptide secondary structure was also studied. Our CD results indicate that the peptide is in a random conformation in aqueous solution at both acidic and basic pH, whereas in the presence of dodecylphosphocholine (DPC) micelles, it assumes a partial alpha-helical structure which is significantly pH-dependent. An NMR study confirmed that, in the presence of DPC micelles, a short C-terminal alpha-helix is present at pH 6.5, whereas almost two-thirds of the peptide (residues 10-26) fold into an extended amphipathic alpha-helix at pH 4.0. The orientation of Pol peptide relative to the DPC micelle was investigated using paramagnetic probes at both pH 4.0 and 6.5. These studies show that the peptide inserts deeply into the micelle at pH 4.0, whereas it is more exposed to the aqueous environment at pH 6.5. On the basis of these results, a model which might explain the mechanism of translocation of Pol peptide from acidic endosomes to the cytosol is discussed.

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Is allostery a fuzzy concept?

Morea,

Angelucci,

Bellelli

2024

FEBS Open Bio

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Allostery is an important property of biological macromolecules which regulates diverse biological functions such as catalysis, signal transduction, transport, and molecular recognition. However, the concept was expressed using two different definitions by J. Monod and, over time, more have been added by different authors, making it fuzzy. Here, we reviewed the different meanings of allostery in the current literature and found that it has been used to indicate that the function of a protein is regulated by heterotropic ligands, and/or that the binding of ligands and substrates presents homotropic positive or negative cooperativity, whatever the hypothesized or demonstrated reaction mechanism might be. Thus, proteins defined to be allosteric include not only those that obey the two‐state concerted model, but also those that obey different reaction mechanisms such as ligand‐induced fit, possibly coupled to sequential structure changes, and ligand‐linked dissociation‐association. Since each reaction mechanism requires its own mathematical description and is defined by it, there are many possible ‘allosteries’. This lack of clarity is made even fuzzier by the fact that the reaction mechanism is often assigned imprecisely and/or implicitly in the absence of the necessary experimental evidence. In this review, we examine a list of proteins that have been defined to be allosteric and attempt to assign a reaction mechanism to as many as possible.

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Crystal Structure of the B Subunit of Escherichia coli Heat-labile Enterotoxin Carrying Peptides with Anti-herpes Simplex Virus Type 1 Activity

Cited by 10 publications

References 36 publications

Structural bioinformatic analysis of DsbA proteins and their pathogenicity associated substrates

Structural bioinformatic analysis of DsbA proteins and their pathogenicity associated substrates

pH-Dependent Conformational Changes and Topology of a Herpesvirus Translocating Peptide in a Membrane-Mimetic Environment

Is allostery a fuzzy concept?

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