https://elifesciences.org/articles/52978 Abstract Previous studies demonstrated importance of C-mannosylation for efficient protein secretion. To study its impact on protein folding and stability, we analyzed both C-mannosylated and non-C-mannosylated thrombospondin type 1 repeats (TSRs) of netrin receptor UNC-5. In absence of C-mannosylation, UNC-5 TSRs could only be obtained at low temperature and a significant proportion displayed incorrect intermolecular disulfide bridging, which was hardly observed when C-mannosylated. Glycosylated TSRs exhibited higher resistance to thermal and reductive denaturation processes, and the presence of C-mannoses promoted the oxidative folding of a reduced and denatured TSR in vitro. Molecular dynamics simulations supported the experimental studie...
https://www.tandfonline.com/doi/ref/10.1080/22221751.2019.1700762?scroll=top ABSTRACT Transition metals participate in numerous enzymatic reactions and they are essential for survival in all living organisms. For this reason, bacterial pathogens have evolved dedicated machineries to effectively compete with their hosts and scavenge metals at the site of infection. In this study, we investigated the mechanisms controlling metal acquisition in the emerging human pathogen Mycoplasma genitalium. We observed a robust transcriptional response to metal starvation, and many genes coding for predicted lipoproteins and ABC-transporters were significantly up-regulated. Transcriptional analysis of a mutant strain lacking a metalloregulator of the Fur family revealed the activation of a f
Cells 2020, 9(1), 145; https://doi.org/10.3390/cells9010145 Abstract Protein aggregation is associated with an increasing number of human disorders and premature aging. Moreover, it is a central concern in the manufacturing of recombinant proteins for biotechnological and therapeutic applications. Nevertheless, the unique architecture of protein aggregates is also exploited by nature for functional purposes, from bacteria to humans. The relevance of this process in health and disease has boosted the interest in understanding and controlling aggregation, with the concomitant development of a myriad of algorithms aimed to predict aggregation propensities. However, most of these programs are blind to the protein environment and, in particular, to the influence of the p
https://doi.org/10.1002/adma.201907348 Abstract Functional amyloids produced in bacteria as nanoscale inclusion bodies are intriguing but poorly explored protein materials with wide therapeutic potential. Since they release functional polypeptides under physiological conditions, these materials can be potentially tailored as mimetic of secretory granules for slow systemic delivery of smart protein drugs. To explore this possibility, bacterial inclusion bodies formed by a self‐assembled, tumor‐targeted Pseudomonas exotoxin (PE24) are administered subcutaneously in mouse models of human metastatic colorectal cancer, for sustained secretion of tumor‐targeted therapeutic nanoparticles. These proteins are functionalized with a peptidic ligand of CXCR4, a chemokine receptor overexpressed
Abstract Five peptide ligands of four different cell surface receptors (nucleolin, CXCR1 CMKLR1 and CD44v6) have been evaluated as targeting moieties for triple-negative human breast cancers. Among them, the peptide F3, derived from phage display, promotes the fast and efficient internalization of a genetically fused GFP inside MDA-MB-231 cancer stem cells, in a specific receptor-dependent fashion. The further engineering of this protein into the modular construct F3-RK-GFP-H6 and the subsequent construct F3-RK-PE24-H6, resulted in self-assembling polypeptides that organize as discrete and regular nanoparticles. These materials, of 15-20 nm in size, show enhanced nucleolin-dependent cell penetrability. We show that the F3-RK-PE24-H6, based on the Pseudomonas aeruginosa exotoxin A (PE24)...
Un nou treball de la UAB-IBB, el l'CIBER-BBN, i l'Hospital de Sant Pau ha desenvolupat un nou biomaterial per a l'alliberament de fàrmacs continuat en el temps. Els resultats han estat publicats a Advanced Science i descriuen la creació de cossos d'inclusió artificials per a usos en biotecnologia i nanomedicina de precisió. La medicina de precisió està prenent un gran protagonisme en els nostres dies, aconseguint teràpies personalitzades més eficaçes per a cada pacient i desenvolupaments farmacològics innovadors. En el camp de l'oncologia, per exemple, s'estan desenvolupant diferents aproximacions orientades a l'alliberament dirigida i controlada dels medicaments disminuint la seva toxicitat en l'organisme. En aquest sentit, investigadors de l'CIBER de Bioenginyeria, Biomaterials i Nan
Front. Mol. Neurosci., 17 December 2019 | https://doi.org/10.3389/fnmol.2019.00306 α-Synuclein (α-Syn) forms toxic intracellular protein inclusions and transmissible amyloid structures in Parkinson’s disease (PD). Preventing α-Syn self-assembly has become one of the most promising approaches in the search for disease-modifying treatments for this neurodegenerative disorder. Here, we describe the capacity of a small molecule (ZPD-2), identified after a high-throughput screening, to inhibit α-Syn aggregation. ZPD-2 inhibits the aggregation of wild-type α-Syn and the A30P and H50Q familial variants in vitro at substoichiometric compound:protein ratios. In addition, the molecule prevents the spreading of α-Syn seeds in protein misfolding cyclic amplification assays. ZPD-2 is active against di
En un artículo publicado ayer en la revista Communications Biology, investigadores del IRTA-Instituto de Biotecnología y Biomedicina (IBB), en la Universidad Autónoma de Barcelona (UAB), y de la Universidad de Bergen y del Instituto de Investigación Marina en Noruega, presentan el descubrimiento y el origen evolutivo de una nueva subfamilia de canales de agua (acuaporinas) que puede desempeñar una función importante en la adaptación de los peces a los cambios de la salinidad ambiental. Los peces han evolucionado adaptaciones fisiológicas distintas para la vida en agua dulce o en ambientes marinos. En las especies de agua dulce el principal mecanismo fisiológico es evitar la entrada masiva de agua al organismo debido a la condición hiperosmótica de sus fluidos corporales, mientras que lo
http://engine.scichina.com/publisher/scp/journal/SCMs/doi/10.1007/s40843-019-1231-y?slug=abstract Abstract Poly-histidine peptides such H6 (HHHHHH) are used in protein biotechnologies as purification tags, protein-assembling agents at the nanoscale and endosomal-escape entities. The pleiotropic properties of such peptides make them appealing to design protein-based smart materials or nanoparticles for imaging or drug delivery to be produced in form of recombinant proteins. However, the clinical applicability of H6-tagged proteins is restricted by the potential immunogenicity of these segments. In this study we have explored several humanized histidine-rich peptides in tumor-targeted modular proteins than bind and internalize cells through the tumoral marker CXCR4. We were particu...
https://www.sciencedirect.com/science/article/pii/S1742706119308050?via%3Dihub DOI information: 10.1016/j.actbio.2019.12.003 Abstract Fluorescent proteins are useful imaging and theranostic agents, but their potential superiority over alternative dyes is weakened by substantial photobleaching under irradiation. Enhancing protein photostability has been attempted through diverse strategies, with irregular results and limited applicability. In this context, we wondered if the controlled oligomerization of Green Fluorescent Protein (GFP) as nanoscale supramolecular complexes could stabilize the fluorophore through the newly formed protein-protein contacts, and thus, enhance its global photostability. For that, we have here analyzed the photobleaching profile of several GFP versions,