Annalisa Pastore

Bio: Annalisa Pastore is an academic researcher from King's College London. The author has contributed to research in topics: Frataxin & Protein structure. The author has an hindex of 66, co-authored 314 publications receiving 14421 citations. Previous affiliations of Annalisa Pastore include National Institute for Medical Research & Francis Crick Institute.

EGCG redirects amyloidogenic polypeptides into unstructured, off-pathway oligomers.

Abstract: The accumulation of beta-sheet-rich amyloid fibrils or aggregates is a complex, multistep process that is associated with cellular toxicity in a number of human protein misfolding disorders, including Parkinson's and Alzheimer's diseases. It involves the formation of various transient and intransient, on- and off-pathway aggregate species, whose structure, size and cellular toxicity are largely unclear. Here we demonstrate redirection of amyloid fibril formation through the action of a small molecule, resulting in off-pathway, highly stable oligomers. The polyphenol (-)-epigallocatechin gallate efficiently inhibits the fibrillogenesis of both alpha-synuclein and amyloid-beta by directly binding to the natively unfolded polypeptides and preventing their conversion into toxic, on-pathway aggregation intermediates. Instead of beta-sheet-rich amyloid, the formation of unstructured, nontoxic alpha-synuclein and amyloid-beta oligomers of a new type is promoted, suggesting a generic effect on aggregation pathways in neurodegenerative diseases.

The structure of melittin. A 1H-NMR study in methanol.

Abstract: The conformation of the 26-residue polypeptide melittin has been studied using 1H-NMR spectroscopy in methanolic solution. The 1H-NMR spectrum of melittin has been assigned using two-dimensional NMR techniques and the secondary structure has been calculated from nuclear Overhauser enhancement data using distance geometry and restrained molecular dynamics analyses. The structure is found to be mainly helical, and similar to that found in crystals from diffraction data: residues 2 – 11 and 13 – 26 form regular α-helices joined by a ‘hinge’ between residues 11 – 12. The structure in this hinge region is shown to be significantly different from that in the crystal structure, leading to a smaller angle between the two helices. The possible significance of the praline residues in this and similar membrane-spanning peptides is discussed.

The solution structure of human epidermal growth factor

Abstract: The epidermal growth factors (EGFs)1–3are powerful mitogens for a wide variety of cells in culture4; human EGF (hEGF), known as urogastrone, also inhibits gastric acid secretion in vivo1. The transforming growth factors (TGF-α) are related to the EGF family both in sequence5 and activity6,7and EGF-like sequences are often observed in a wide range of functionally unrelated proteins8. Attempts to examine the structure of EGF by diffraction methods have not yet succeeded because of difficulties with crystallization. We report here a three-dimensional structure of a biologically active derivative (residues 1–48) of the 53-residue human EGF. An analysis of high resolution 1H nuclear magnetic resonance (NMR) spectra was used together with a combination of distance geometry, restrained energy minimization and restrained molecular dynamics methods. The three-dimensional structure provides a basis for understanding the properties of EGFs and for predicting the structures of homologous sequences in other proteins.

Mutations in the mitochondrial protease gene AFG3L2 cause dominant hereditary ataxia SCA28

Abstract: Autosomal dominant spinocerebellar ataxias (SCAs) are genetically heterogeneous neurological disorders characterized by cerebellar dysfunction mostly due to Purkinje cell degeneration. Here we show that AFG3L2 mutations cause SCA type 28. Along with paraplegin, which causes recessive spastic paraplegia, AFG3L2 is a component of the conserved m-AAA metalloprotease complex involved in the maintenance of the mitochondrial proteome. We identified heterozygous missense mutations in five unrelated SCA families and found that AFG3L2 is highly and selectively expressed in human cerebellar Purkinje cells. m-AAA-deficient yeast cells expressing human mutated AFG3L2 homocomplex show respiratory deficiency, proteolytic impairment and deficiency of respiratory chain complex IV. Structure homology modeling indicates that the mutations may affect AFG3L2 substrate handling. This work identifies AFG3L2 as a novel cause of dominant neurodegenerative disease and indicates a previously unknown role for this component of the mitochondrial protein quality control machinery in protecting the human cerebellum against neurodegeneration.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

“Bioinformatics” 특집을 내면서

Abstract: BIOE 402. Medical Technology Assessment. 2 or 3 hours. Bioentrepreneur course. Assessment of medical technology in the context of commercialization. Objectives, competition, market share, funding, pricing, manufacturing, growth, and intellectual property; many issues unique to biomedical products. Course Information: 2 undergraduate hours. 3 graduate hours. Prerequisite(s): Junior standing or above and consent of the instructor.

Human MicroRNA Targets

Abstract: MicroRNAs (miRNAs) interact with target mRNAs at specific sites to induce cleavage of the message or inhibit translation. The specific function of most mammalian miRNAs is unknown. We have predicted target sites on the 3′ untranslated regions of human gene transcripts for all currently known 218 mammalian miRNAs to facilitate focused experiments. We report about 2,000 human genes with miRNA target sites conserved in mammals and about 250 human genes conserved as targets between mammals and fish. The prediction algorithm optimizes sequence complementarity using position-specific rules and relies on strict requirements of interspecies conservation. Experimental support for the validity of the method comes from known targets and from strong enrichment of predicted targets in mRNAs associated with the fragile X mental retardation protein in mammals. This is consistent with the hypothesis that miRNAs act as sequence-specific adaptors in the interaction of ribonuclear particles with translationally regulated messages. Overrepresented groups of targets include mRNAs coding for transcription factors, components of the miRNA machinery, and other proteins involved in translational regulation, as well as components of the ubiquitin machinery, representing novel feedback loops in gene regulation. Detailed information about target genes, target processes, and open-source software for target prediction (miRanda) is available at http://www.microrna.org. Our analysis suggests that miRNA genes, which are about 1% of all human genes, regulate protein production for 10% or more of all human genes.

Protein backbone angle restraints from searching a database for chemical shift and sequence homology

Abstract: Chemical shifts of backbone atoms in proteins are exquisitely sensitive to local conformation, and homologous proteins show quite similar patterns of secondary chemical shifts. The inverse of this relation is used to search a database for triplets of adjacent residues with secondary chemical shifts and sequence similarity which provide the best match to the query triplet of interest. The database contains 13Cα, 13Cβ, 13C′, 1Hα and 15N chemical shifts for 20 proteins for which a high resolution X-ray structure is available. The computer program TALOS was developed to search this database for strings of residues with chemical shift and residue type homology. The relative importance of the weighting factors attached to the secondary chemical shifts of the five types of resonances relative to that of sequence similarity was optimized empirically. TALOS yields the 10 triplets which have the closest similarity in secondary chemical shift and amino acid sequence to those of the query sequence. If the central residues in these 10 triplets exhibit similar φ and Ψ backbone angles, their averages can reliably be used as angular restraints for the protein whose structure is being studied. Tests carried out for proteins of known structure indicate that the root-mean-square difference (rmsd) between the output of TALOS and the X-ray derived backbone angles is about 15°. Approximately 3% of the predictions made by TALOS are found to be in error.

Reversible Unfolding of Individual Titin Immunoglobulin Domains by AFM

Abstract: Single-molecule atomic force microscopy (AFM) was used to investigate the mechanical properties of titin, the giant sarcomeric protein of striated muscle. Individual titin molecules were repeatedly stretched, and the applied force was recorded as a function of the elongation. At large extensions, the restoring force exhibited a sawtoothlike pattern, with a periodicity that varied between 25 and 28 nanometers. Measurements of recombinant titin immunoglobulin segments of two different lengths exhibited the same pattern and allowed attribution of the discontinuities to the unfolding of individual immunoglobulin domains. The forces required to unfold individual domains ranged from 150 to 300 piconewtons and depended on the pulling speed. Upon relaxation, refolding of immunoglobulin domains was observed.