Structural basis of binding the unique N-terminal domain of microtubule-associated protein 2c to proteins regulating kinases of signaling pathways.

Isoforms of microtubule-associated protein 2 (MAP2) differ from their homolog Tau in the sequence and interactions of the N-terminal region. Binding of the N-terminal region of MAP2c (N-MAP2c) to the dimerization/docking domains of the regulatory subunit RIIα of cAMP-dependent protein kinase (RIIDD) and to the Src-homology domain 2 (SH2) of growth factor receptor-bound protein 2 (Grb2) have been described long time ago. However, the structural features of the complexes remained unknown due to the disordered nature of MAP2.

Changes in Endometriosis-Associated Symptoms Following Immunization against SARS-CoV-2: A Cross-Sectional Study.

: There are many reports about variations in the menstrual cycle after infection with SARS-CoV-2 or vaccination against it. However, data on SARS-CoV-2 infection or vaccination-related changes in menstruation-associated endometriosis-typical symptoms such as dysmenorrhea, dyspareunia, dyschezia, dysuria, and bloating are rare or missing. : This retrospective study was performed as an online survey among employees and students at the University Hospital Ulm, Germany.

Disturbances of menstrual cycle after immunization against SARS-CoV-2 and their risk factors: Cross-sectional clinical study.

Objective: Abnormalities of the menstrual cycle were reported after infection with SARS-CoV-2 and vaccination against it, but the available data are very heterogeneous, do not reflect intermenstrual variations or regional differences, and their risk factors are missing.

Methods: We performed a survey-based study among 6383 employees and students of Ulm University Hospital in Germany between March 1 and 31, 2021. Attributes of menstrual cycles such as cycle length (CL), menses duration (MD), and bleeding volume (BV) were reported as categorical variables before and after immunization against SARS-CoV-2 (first, second, third vaccination or infection).

Macromolecular Crowding Induces a Binding Competent Transient Structure in Intrinsically Disordered Gab1.

Intrinsically disordered proteins (IDPs) are an important class of proteins which lack tertiary structure elements. Their dynamic properties can depend on reversible post-translational modifications and the complex cellular milieu, which provides a crowded environment. Both influences the thermodynamic stability and folding of globular proteins as well as the conformational plasticity of IDPs.

Lipid-Dependent Interaction of Human N-BAR Domain Proteins with Sarcolemma Mono- and Bilayers.

The N-BAR domain of the human Bin1 protein is indispensable for T-tubule biogenesis in skeletal muscles. It binds to lipid mono- and bilayers that mimic the sarcolemma membrane composition, and it transforms vesicles into uniform tubules by generating a decorating protein scaffold. We found that Δ(1-33)BAR, lacking the N-terminal amphipathic helix (H0), and H0 alone bind to sarcolemma monolayers, although both proteins are not able to tubulate sarcolemma vesicles.

Synthetic Receptors for the Recognition and Discrimination of Post-Translationally Methylated Lysines.

Post-translational modifications (PTMs) describe the chemical alteration of proteins after their biosynthesis in ribosomes. PTMs play important roles in cell biology, including the regulation of gene expression, cell-cell interactions and the development of different diseases. A prominent class of PTMs is the side-chain methylation of lysine.

Multifunctional Efficiency: Extending the Concept of Atom Economy to Functional Nanomaterials.

Green chemistry, in particular, the principle of atom economy, has defined new criteria for the efficient and sustainable production of synthetic compounds. In complex nanomaterials, the number of embedded functional entities and the energy expenditure of the assembly process represent additional compound-associated parameters that can be evaluated from an economic viewpoint. In this Perspective, we extend the principle of atom economy to the study and characterization of multifunctionality in nanocarriers, which we define as "multifunctional efficiency".

Different supramolecular interactions mediated by Br atoms in the crystal structures of three anisole derivatives.

Three anisole building blocks featuring bis(hydroxymethyl) or bis(bromomethyl) pendants have been analyzed with regard to their molecular structures and packing behaviour. The compounds are ethyl 3,5-bis(hydroxymethyl)-4-methoxybenzoate, CHO, (I), [5-bromo-3-(hydroxymethyl)-2-methoxyphenyl]methanol [or 4-bromo-2,6-bis(hydroxymethyl)anisole], CHBrO, (II), and 5-bromo-1,3-bis(bromomethyl)-2-methoxybenzene [or 4-bromo-2,6-bis(bromomethyl)anisole], CHBrO, (III). A typical supramolecular pattern involved C-H.

Selective recognition of the di/trimethylammonium motif by an artificial carboxycalixarene receptor.

Chemical tools that recognise post-translational modifications have promising applications in biochemistry and in therapy. We report a simple carboxycalixarene that selectively binds molecules containing di/trimethylammonium moieties in isolation, in cell lysates and when incorporated in histone peptides. Our findings reveal the potential of using carboxycalixarene-based receptors to study epigenetic regulation.

Crystal structures of functional building blocks derived from bis(benzo[b]thiophen-2-yl)methane.

The syntheses of three bis(benzo[b]thiophen-2-yl)methane derivatives, namely bis(benzo[b]thiophen-2-yl)methanone, C17H10OS2, (I), 1,1-bis(benzo[b]thiophen-2-yl)-3-(trimethylsilyl)prop-2-yn-1-ol, C22H20OS2Si, (II), and 1,1-bis(benzo[b]thiophen-2-yl)prop-2-yn-1-ol, C19H12OS2, (III), are described and their crystal structures discussed comparatively. The conformation of ketone (I) and the respective analogues are rather similar for most of the compounds compared. This is true for the interplanar angles, the Caryl-Cbridge-Caryl angles and the dihedral angles.

Supramolecular organization of the human N-BAR domain in shaping the sarcolemma membrane.

The 30kDa N-BAR domain of the human Bin1 protein is essential for the generation of skeletal muscle T-tubules. By electron cryo-microscopy and electron cryo-tomography with a direct electron detector, we found that Bin1-N-BAR domains assemble into scaffolds of low long-range order that form flexible membrane tubules. The diameter of the tubules closely matches the curved shape of the N-BAR domain, which depends on the composition of the target membrane.

Protein Folding Mechanism of the Dimeric AmphiphysinII/Bin1 N-BAR Domain.

The human AmphyphisinII/Bin1 N-BAR domain belongs to the BAR domain superfamily, whose members sense and generate membrane curvatures. The N-BAR domain is a 57 kDa homodimeric protein comprising a six helix bundle. Here we report the protein folding mechanism of this protein as a representative of this protein superfamily.

Consequences of proline-to-alanine substitutions for the stability and refolding of onconase.

Peptidyl-prolyl isomerization reactions can make for rate-limiting steps in protein folding due to their high activation energy. Onconase, an unusually stable ribonuclease A homologue from the Northern leopard frog, contains four trans proline residues in its native state. During the refolding from its guanidine hydrochloride unfolded state, which includes the formation of a folding intermediate, the slowest of the three phases has earlier been attributed to a cis-to-trans peptidyl-prolyl isomerization reaction.

3-Meth-oxy-3-oxopropanaminium chloride.

In the title compound, C(4)H(10)NO(2) (+)·Cl(-), the central ethyl-ene bond of the cation adopts a gauche conformation. The three H atoms of the -NH(3) (+) group are engaged in strong and highly directional inter-molecular N-H⋯Cl hydrogen bonds, which result in a tape-like arrangement along [010] of the respective ion pairs. In addition, weak inter-molecular C-H⋯Cl and C-H⋯O inter-actions are present.

Methyl 6-amino-6-oxohexa-noate.

The title compound, C(7)H(13)NO(3), adopts an approximately planar conformation. The torsion angles in the aliphatic chain between the carbonyl group C atoms range from 172.97 (14) to 179.

1-Methyl-4-(4-nitro-benzo-yl)pyridinium perchlorate.

In the main mol-ecule of the title compound, C(13)H(11)N(2)O(3) (+)·ClO(4) (-), the two aromatic rings are twisted by 56.19 (3)° relative to each other and the nitro group is not coplanar with the benzene ring [36.43 (4)°].

Bridge-substituted calix[4]arenes: syntheses, conformations and application.

The bridge-substituted calix[4]arene carboxylic acid, 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetramethoxy-calix[4]arene-2-carboxylic acid (1), can be readily converted to various esters 2-4 and reduced to the alcohol 5, which reacts with methyl iodide to give the ether 6. The alcohol can be dansylated to give 7, the fluorescence of which is selectively quenched by Cu(II) in acetonitrile. An attempt to convert the acid 1 to an amide resulted unexpectedly in the formation of a lactone 8.

25-Allyloxy-5,11,17,23-tetra-tert-butyl-26,27,28-trihydroxycalix[4]arene chloroform disolvate.

In the title solvated calixarene, C(47)H(60)O(4) x 2 CHCl(3), the host chalice displays an almost undistorted cone conformation, stabilized by three strong O-H...

1-(Hydroxy-meth-yl)pyrene.

The asymmetric unit of the title compound, C(17)H(12)O, contains two molecules, in which the fused aromatic ring systems are almost planar [maximum deviations = 0.0529 (9) and 0.0256 (9) Å].

Calix[4]arenes featuring a direct lower rim attachment of dansyl groups. Synthesis, fluorescence properties and first report on crystal structures.

A series of new fluorescent calix[4]arenes (2-7; 5 has been isolated as two not yet described conformational isomers) featuring two directly lower rim attached dansyl moieties besides other lower or upper rim site substituents have been synthesized and investigated with reference to their fluorescence properties including potential sensing capability for metal ions. Except for the nitro substituted compound 7, which showed a moderate fluorescence quenching on the addition of Hg2+ in acetonitrile, the calixarenes 2-6 were found to selectively recognize Cu2+ in the 10(-6) mol L(-1) concentration range detectable by the nearly total quenching of their intrinsic fluorescence. Using fluorescence titration experiments, the ideal complexation ratio [metal ion]/[ligand] for three exemplarily investigated calixarenes (3, 5a and 7) was determined to be 2:1.

N-Cyclo-dodecyl-5-(dimethyl-amino)-naphthalene-1-sulfonamide.

The molecule of the title compound, C(24)H(36)N(2)O(2)S, displays a U-shaped conformation. The prominent inter-molecular inter-actions are N-H⋯O hydrogen bonds, resulting in the formation of dimers. Additional C-H⋯π contacts involving one of the methyl-ene groups of the macrocycle and the naphthalene rings of a neighbouring mol-ecule stabilize the packing structure.

5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetra-methoxy-calix[4]arene dichloro-methane hemisolvate.

In the title compound, C(48)H(64)O(4)·0.5CH(2)Cl(2), both crystallographically independent calixarene mol-ecules display a partial cone conformation. Their crystal packing is stabilized by C-H⋯π contacts involving the meth-oxy groups.