An orthogonally protected CycloTriVeratrylene (CTV) as a highly pre-organized molecular scaffold for subsequent ligation of different cyclic peptides towards protein mimics

The synthesis of a semi-orthogonally protected CycloTriVeratrilene (CTV) scaffold derivative as well as the sequential introduction of three different peptide loops onto this molecular scaffold via Cu(I)-catalyzed azide alkyne cycloaddition towards a medium-sized protein mimic is described. This approach for the construction of medium-sized protein mimics is illustrated by the synthesis of a paratope mimic of the monoclonal antibody Infliximab (Remicade®) and provides access to a range of highly pre-organized molecular constructs bearing three different peptide segments. This approach may find wide applications for development of protein-protein interaction disruptors as well as synthetic vaccines

Potential peptidic proteasome inhibitors by incorporation of an electrophilic trap based on amino acid derived α-substituted sulfonyl fluorides

Peptido sulfonyl fluoride derivatives were designed and synthesized containing a substituent on the alpha position (αPSFs) with respect to the sulfonyl fluoride electrophilic trap. The chemical reactivity of these α-substituted amino sulfonyl fluorides was studied and compared with the previously described β-substituted amino sulfonyl fluorides in order to get a deeper insight into the importance of the immediate structural environment of the sulfonyl fluoride moiety. Unfortunately, the poor solubility of the resulting αPSFs precluded a proper evaluation of their biological activity

Tailoring polyethers for efficient post-polymerization functionalization by cross metathesis

Olefin cross metathesis is reported for the first time to attach small molecules to a range of novel polyethers with a poly(ethylene glycol) backbone and pendent alkene groups, allowing for a loading of up to one compound per monomer unit. These polymers are tailored to prevent the occurrence of self metathesis (reaction of the polymer with itself) by varying the substitution on the pendent alkenes, thus steering their reactivity toward olefin cross metathesis. Efficient functionalization has been observed for a range of coupling partners as a proof of concept for the use of olefin metathesis to graft small and larger molecules to polyethers for drug delivery. This approach also paves the way for the use of olefin cross metathesis as an efficient method to functionalize a wide variety of polymers with pendent olefin groups

Proteasome inhibition by new dual warhead containing peptido vinyl sulfonyl fluorides

The success of inhibition of the proteasome by formation of covalent bonds is a major victory over the long held-view that this would lead to binding the wrong targets and undoubtedly lead to toxicity. Great challenges are now found in uncovering ensembles of new moieties capable of forming long lasting ties. We have introduced peptido sulfonyl fluorides for this purpose. Tuning the reactivity of this electrophilic trap may be crucial for modulating the biological action. Here we describe incorporation of a vinyl moiety into a peptido sulfonyl fluoride backbone, which should lead to a combined attack of the proteasome active site threonine on the double bond and the sulfonyl fluoride. Although this led to strong proteasome inhibitors, in vitro studies did not unambiguously demonstrate the formation of the proposed seven-membered ring structure. Possibly, formation of a seven-membered covalent adduct with the proteosomal active site threonine can only be achieved within the context of the enzyme. Nevertheless, this dual warhead concept may provide exclusive possibilities for duration and selectivity of proteasome inhibition

Роль органічних речовин води Нафтуся у її фізіологічній активності

В экспериментах на крысах, а также ex vivo, используя воду Нафтуся из различных скважин и в разные периоды ее мониторинга, а также выделенные из Нафтуси ее гидрофобные и гидрофильные органические вещества, выявлено 5 различающихся между собой кластеров физиологических эффектов, обусловленных количественными и качественными различиями органической компоненты Нафтуси.In experiments on rats, and also ex vivo, using water Naftussya from various chinks and in the different periods of her monitoring, and also allocated from Naftussya her hydrophobic and hydrophyle organic substances, is revealed 5 differing among themselves clusters of physiological effects caused by quantitative and qualitative distinctions organic components Naftussya

Synthesis and cellular penetration properties of new phosphonium based cationic amphiphilic peptides

A new category of phosphonium based cationic amphiphilic peptides has been developed and evaluated as potential antimicrobial peptides and cell penetrating peptides. The required building blocks were conveniently accessible from cysteine and could be applied in a solid phase peptide synthesis protocol for incorporation into peptide sequences. Evaluation of the antimicrobial properties and cellular toxicity of these phosphonium based peptides showed that these “soft” cationic side-chain containing peptides have poor antimicrobial properties and most of them were virtually non toxic (on HEK cells tested at 256 and 512 μM) and non-haemolytic (on horse erythrocytes tested at 512 μM), hinting at an interesting potential application as cell penetrating peptides. This possibility was evaluated using fluorescent peptide derivatives and showed that these phosphonium based peptide derivatives were capable of entering HEK cells and depending on the sequence confined to specific cellular areas

Immobilization by surface conjugation of cyclic peptides for effective mimicry of the HCV-envelope E2 protein as a strategy toward synthetic vaccines

Mimicry of the binding interface of antibody-antigen interactions using peptide-based modulators (i.e. epitope mimics) has promising applications for vaccine design. These epitope mimics can be synthesized in a streamlined and straightforward fashion, thereby allowing for high-throughput analysis. The design of epitope mimics is highly influenced by their spatial configuration and structural conformation. It is widely assumed that for proper mimicry sufficient conformational constraints have to be implemented. This paper describes the synthesis of bromide derivatives functional-ized with a flexible TEG linker equipped with a thiol-moiety that could be used to support cyclic or linear peptides. The cyclic and linear epitope mimics were covalently conjugated via the free thiol-moiety on maleimide-activated plate sur-faces. The resulting covalent, uniform, and oriented coated surface of cyclic or linear epitope mimics were subjected to an ELISA to investigate the effect of peptide cyclization with respect to mimicry of an antigen-antibody interaction of the HCV E2 glycoprotein. To our knowledge, the benefit of cyclized peptides over linear peptides has been clearly demon-strated here for the first time. Cyclic epitope mimics, and not the linear epitope mimics, demonstrated specificity towards their monoclonal antibodies HC84.1 and V3.2, respectively. The described strategy for the construction of epitope mimics shows potential for high-throughput screening of key-binding residues by simply changing the amino-acid sequences within synthetic peptides. In this way, leucine-438 has been identified as a key-binding residue for binding monoclonal antibody V3.2

Improving the aqueous solubility of HCV-E2 glycoprotein epitope mimics by cyclization using polar hinges

In this research we describe the improvement of the water‐solubility of cyclic epitope mimics based on the HCV E2 glycoprotein by incorporation of suitable polar hinges. The poor solubility of epitope mimics based on peptide sequences in the envelope (E2) protein hampered their synthesis and purification and made it very difficult to prepare the molecular constructs for evaluation of their bioactivity. Since changes in the amino acid composition are hardly possible in these epitope mimics in order to increase water‐solubility, a polar cyclization hinge may offer a remedy leading to a significant increase of polarity and therefore water solubility. These polar hinges were applied in the synthesis of better water‐soluble HCV‐E2 epitopes. An azide functionality in the polar hinges allowed attachment of a tetraethylene glycol linker by Cu‐catalyzed azide‐alkyne cyclo‐addition (CuAAC) for a convenient conjugation to ELISA plates in order to evaluate the bio‐activity of the epitope mimics. The immunoassays showed that the use of more polar cyclization hinges still supported anti‐HCV antibody recognition and did not negatively influence their binding. This significantly increased solubility induced by polar hinges should therefore allow for the molecular construction and ultimate evaluation of synthetic vaccine molecules

Клінічні особливості генетично детермінованих гіпобета-ліпопротеїнемії та гіпохолестеролемії

Familial hypobetalipoproteinemia (FHBL) is an autosomal dominant disorder of lipid metabolism characterized by extremely low plasma levels of apolipoprotein B, total cholesterol and low-density lipoprotein cholesterol. Heterozygotes for FHBL are often asymptomatic. Clinical features of homozygous FHBL can include acanthocytosis, deficiencies in fat-soluble vitamins secondary to malabsorption, atypical retinitis pigmentosa and neuromuscular abnormalities

Specific N-terminal attachment of TMTHSI linkers to native peptides and proteins for strain-promoted azide alkyne cycloaddition

The site specific attachment of the reactive TMTHSI-click handle to the N-terminus of peptides and proteins is described. The resulting molecular constructs can be used in strain-promoted azide alkyne cycloaddition (SPAAC) for reaction with azide containing proteins e.g., antibodies, peptides, nanoparticles, fluorescent dyes, chelators for radioactive isotopes and SPR-chips etc