13 research outputs found
Protaphycus shuvalikovi Simutnik gen. et sp. nov. (Chalcidoidea, Encyrtidae, Encyrtinae) from Rovno amber
Protaphycus shuvalikovi Simutnik gen. et sp. nov., the smallest fossil Encyrtidae, is described and illustrated based on female specimen from late Eocene Rovno amber. Like most previously described Eocene Encyrtidae, the new taxon differs from the majority of extant encyrtids by the subapical position of the cerci, the relatively long marginal vein of the forewing, a distinctly swollen but not triangular parastigma, and a seta marking the apex of the postmarginal vein is not any longer than others on this vein. The new genus is characterized by the presence of a filum spinosum and the hypopygium reaching way past the apex of syntergum. This combination of the character states is known only in a few representatives of extant Encyrtinae. The new genus, probably, most closely related to the extant genus Aphycus Mayr, 1876
The first reliable fossil record of the tribe Centistini (Hymenoptera, Braconidae, Euphorinae): a new subgenus and species of braconid wasp in Danish amber
A new subgenus and species of the braconid parasitoid of the tribe Centistini s. l. (Euphorinae), Centistoides (Palaeoides) magnioculus Belokobylskij, subgen. et sp. nov., from late Eocene Danish amber are described and illustrated from one female. This is the first time the tribe of euphorine parasitoids is reliably documented in the fossil record. A key to all genera and subgenera of this suprageneric taxonomic group is compiled. The discussion about position of the genus Parasyrrhizus Brues, composition of the tribe Centistini s. l., and the composition of the Danish amber hymenopteran fauna are provided
The American tribes Anypotactini and Eudiagogini (Coleoptera, Curculionidae) in Eocene of Europe as indicators of eocene climate with description a new species
Balticalcarus archibaldi Simutnik Gen. et sp. n. (Chalcidoidea, Encyrtidae) with the Unusually Small Mesotibial Spur from Baltic Amber
Balticalcarus archibaldi Simutnik, gen. et sp. n., is described and illustrated based on a female specimen from late Eocene Baltic amber. The new genus is characterized by the absence of a filum spinosum, a “boat”-shaped hypopygium enclosing the ovipositor, reaching far past the apex of the syntergum, the presence of a line of long setae along the entire costal cell of the hind wing, and a transverse line of thickened setae alongside the hyaline spur vein. Moreover, like most previously described Eocene Encyrtidae, the new taxon differs from the majority of the extant ones by a number of morphological features. The new fossil differs from most extant and all known fossil Encyrtidae by its unusually small, thin, smooth (without microsetae) mesotibial spur
A mid-Cretaceous land snail Euthema truncatellina sp. nov. (Caenogastropoda Cyclophoroidea, Diplommatinidae) from Burmese amber
Balashov, Igor A., Perkovsky, Evgeny E., Vasilenko, Dmitry V. (2020): A mid-Cretaceous land snail Euthema truncatellina sp. nov. (Caenogastropoda Cyclophoroidea, Diplommatinidae) from Burmese amber. Zootaxa 4858 (2): 295-300, DOI: https://doi.org/10.11646/zootaxa.4858.2.1
A Facile Approach to Bis(isoxazoles), Promising Ligands of the AMPA Receptor
A convenient synthetic approach to novel functionalized bis(isoxazoles), the promising bivalent ligands of the AMPA receptor, was elaborated. It was based on the heterocyclization reactions of readily available electrophilic alkenes with the tetranitromethane-triethylamine complex. The structural diversity of the synthesized compounds was demonstrated. In the electrophysiological experiments using the patch clamp technique on Purkinje neurons, the compound 1,4-phenylenedi(methylene)bis(5-aminoisoxazole-3-carboxylate) was shown to be highly potent positive modulator of the AMPA receptor, potentiating kainate-induced currents up to 70% at 10−11 M
Zn\u3csup\u3e2+\u3c/sup\u3e-mediated Structure Formation and Compaction of The “Natively Unfolded” Human Prothymosin α
Human recombinant prothymosin α (ProTα) is known to have coil-like conformation at neutral pH; i.e., it belongs to the class of “natively unfolded” proteins. By means of circular dichroism, SAXS, and ANS fluorescence, we have investigated the effect of several divalent cations on the structure of this protein. Results of these studies are consistent with the conclusion that ProTα conformation is unaffected by large excess of Ca2+, Mg2+, Mn2+, Cu2+, and Ni2+. However, Zn2+ induces compaction and considerable rearrangement of the protein structure. This means that ProTα can specifically interact with Zn2+ (KD ∼ 10−3 M), and such interactions induce folding of the natively unfolded protein into a compact partially folded (premolten globule-like) conformation. It is possible that these structural changes may be important for the function of this protein
Natively unfolded human prothymosin R adopts partially folded collapsed conformation at acidic pH
ABSTRACT: Prothymosin R has previously been shown to be unfolded at neutral pH, thus belonging to a growing family of “natively unfolded ” proteins. The structural properties and conformational stability of recombinant human prothymosin R were characterized at neutral and acidic pH by gel filtration, SAXS, circular dichroism, ANS fluorescence, 1 H NMR, and resistance to urea-induced unfolding. Interestingly, prothymosin R underwent a cooperative transition from the unfolded state into a partially folded conformation on lowering the pH. This conformation of prothymosin R is a compact denatured state, with structural properties different from those of the molten globule. The formation of R-helical structure by the glutamic acid-rich elements of the protein accompanied by the partial hydrophobic collapse is expected at lower pH due to the neutralization of the negatively charged residues. It is possible that such conformational changes may be associated with the protein function. Prothymosin R (ProTR) 1 is an acidic nuclear protein with wide tissue distribution (1, 2), initially isolated from the rat thymus (3). Although the thymus is the richest source of ProTR, the ProTR gene was shown to be expressed in a wide variety of tissues (4). Despite the exact function of ProT