Search results for "MIMICRY"
showing 10 items of 120 documents
The Molecular Anatomy of Human Hsp60 and its Similarity with that of Bacterial Orthologs and Acetylcholine Receptor Reveal a Potential Pathogenetic R…
2012
Heat-shock protein 60 (Hsp60) is ubiquitous and highly conserved being present in eukaryotes and prokaryotes, including pathogens. This chaperonin, although typically a mitochondrial protein, can also be found in other intracellular sites, extracellularly, and in circulation. Thus, it can signal the immune system and participate in the development of inflammation and immune reactions. Both phenomena can be elicited by human and foreign Hsp60 (e.g., bacterial GroEL), when released into the blood by infectious agents. Consequently, all these Hsp60 proteins become part of a complex autoimmune response characterized by multiple cross reactions because of their structural similarities. In this s…
Functional superoxide dismutase mimics. Structural characterization and magnetic exchange interactions of copper(II)-N-substituted sulfonamide dimer …
2004
Dinuclear copper(II) complexes with N-substituted sulfonamide ligands as superoxide dismutase (SOD) mimics have been investigated. The new N-(thiazol-2-yl)toluenesulfonamide (Htz-tol) and N-(thiazol-2-yl)naphthalenesulfonamide (Htz-naf) ligands have been prepared and structurally characterized. The complexes derived from these ligands, [Cu(2)(tz-tol)(4)] (1) and [Cu(2)(tz-naf)(4)] (2), have been synthesized, and their crystal structure, magnetic properties, and EPR spectra were studied in detail. In both compounds the metal centers are bridged by four nonlinear triatomic NCN groups. The coordination geometry of the coppers in the dinuclear entity of 1 and 2 is distorted square planar with t…
Toward very potent, non-covalent organophosphonate inhibitors of cathepsin C and related enzymes by 2-amino-1-hydroxy-alkanephosphonates dipeptides
2013
Cathepsins play an important role in several human disorders and therefore the design and synthesis of their inhibitors attracts considerable interest in current medicinal chemistry approaches. Due to the presence of a strong sulphydryl nucleophile in the active center of the cysteine type cathepsins, most strategies to date have yielded covalent inhibitors. Here we present a series of non-covalent β-amino-α-hydroxyalkanephosphonate dipeptidic inhibitors of cathepsin C, ranking amongst the best low-molecular weight inhibitors of this enzyme. Their binding modes determined by molecular modelling indicate that the hydroxymethyl fragment of the molecule, not the phosphonate moiety, acts as a t…
Machine Learning Unveils Proteotypic Mimicry in Genetically Defined SCN Variants
2019
Background Novel computational algorithms for multi-omics analysis bear great potential to highlight pathomechanisms of monogenic diseases. We recently defined the in-depth proteome of primary human neutrophil granulocytes (PMID 30630937). Here, we ask the question whether proteotypic patterns differ between defined genetic subtypes associated with severe congenital neutropenia (SCN). We focus on two novel genetic variants in constituents of the signal recognition particle (SRPRA and SRP19) and previously reported SCN genotypes SRP54, HAX1, and ELANE. Methods We analyzed proteomes of highly purified neutrophil granulocytes from a total of 26 SCN patients, including 5 with homozygous splice …
How Did the Cuckoo Get Its Polymorphic Plumage?
2012
One hundred and fifty years ago, the English naturalist Henry Walter Bates first developed the theory of mimicry ( 1 ). Based on his field observations in the Amazon, he argued that the uncanny likeness of unrelated butterflies is an evolutionary adaptation whereby edible butterflies avoid predation by imitating the coloration of venomous butterfly species without paying the cost of arming themselves. Such “Batesian mimicry” is a dynamic parasitic game between three players, in which a harmless species (the mimic) escapes predation by imitating the warning signals of harmful species (the model) that a shared predator (the dupe) has learned to avoid. On page 578 of this issue, Thorogood and …
Trait empathy modulates music-related functional connectivity
2021
It has been well established through behavioural studies that empathy significantly influences music perception. Such individual differences typically manifest as variability in whole brain functional connectivity patterns. To date, nobody has examined the modulatory effect of empathy on functional connectivity patterns during continuous music listening. In the present study, we seek to investigate the global and local connectivity patterns of 36 participants whose fMRI scanning was done by employing the naturalistic paradigm wherein they listened to a continuous piece of music. We used graph-based measures of functional connectivity to identify how cognitive and affective components of emp…
Aggressive mimicry coexists with mutualism in an aphid
2015
Understanding the evolutionary transition from interspecific exploitation to cooperation is a major challenge in evolutionary biology. Ant-aphid relationships represent an ideal system to this end because they encompass a coevolutionary continuum of interactions ranging from mutualism to antagonism. In this study, we report an unprecedented interaction along this continuum: aggressive mimicry in aphids. We show that two morphs clonally produced by the aphid Paracletus cimiciformis during its root-dwelling phase establish relationships with ants at opposite sides of the mutualism-antagonism continuum. Although one of these morphs exhibits the conventional trophobiotic (mutualistic) relations…
Human parvovirus B19 infection and antiphospholipid antibodies
2007
Erythema infectiosum is the main manifestation of human parvovirus B19 infections. Further B19-related diseases commonly associated with the acute infection are flue-like symptoms, transient aplastic crisis, transient arthralgias, leukopenia and thrombocytopenia, spontaneous abortion and hydrops fetalis in pregnant women. Hepatitis, myocarditis, meningitis, encephalitis as well as pure red cell anemia may occur occasionally. In addition parvovirus B19 infections have been frequently described as cause or trigger of various forms of autoimmune diseases affecting all blood cell lines, joints, connective tissue, uvea, large and small vessels. Molecular mimicry may be one major contribution to …
Effects of novelty and gregariousness in survival of aposematic prey
1997
We examined the reactions of captive wild great tits to novel unpalatable prey with (1) a traditional aposematic signal (black and yellow) (2) a novel signal (light pink), and (3) a control signal (brown). Prey were offered either singly or in groups to see whether novel signals with fewer possibilities for synergistic benefits are more dependent on grouping than are the traditional signals. Indeed, responses of birds toward unpalatable prey depended significantly on spatial distribution of prey (grouping versus solitary) and die type of die signal. Birds avoided more the traditional black and yellow signals than novel pink signals in both experimental set ups, but both of diese prey items …
Co-mimics have a mutualistic relationship despite unequal defences
2007
Defensive mimicry, where species have evolved to resemble others in order to evade predators, is quite common in the animal kingdom. The two extremes of the mimicry spectrum are known as 'batesian' and 'mullerian'. Batesian mimics develop signals — visual cues for instance — that are similar to those of species being mimicked, but stop short of adopting the attribute that makes it unprofitable prey to predators. Mullerian mimics both resemble the model species and share the anti-predation attribute — by being dangerous or unpalatable. These different types of mimic were identified a century ago, but the dynamics of mimicry between unequally defended prey remain unresolved. In an experiment …