Non-native glyceraldehyde-3-phosphate dehydrogenase can be an intrinsic component of amyloid structures

Interactions between different forms of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and amyloid-beta peptide (1-42) were investigated by direct (surface plasmon resonance) and indirect (kinetics of spontaneous and GroEL/S-assisted reactivation of denatured GAPDH) methods. It was demonstrated that non-native forms of GAPDH obtained by different ways (cold denaturation, oxidation of the enzyme, and its unfolding in guanidine hydrochloride) efficiently bind to soluble amyloid-beta peptide (1-42) yielding a stable complex. Native tetrameric GAPDH does not interact with soluble amyloid-beta peptide (1-42), neither non-native forms of GAPDH interact with aggregated amyloid-beta peptide (1-42). The results suggest that non-native GAPDH species can be involved in the formation of amyloid structures during Alzheimer's disease, binding to soluble amyloid-beta peptide (1-42).     

An antibiotic complex produced by Streptomyces werraensis 1365T strain

An antibiotic complex comprising four components (A, B, C, and X) was extracted from a native solution and mycelium of Streptomyces werraensis 1365T. The components were purified by column and thin-layer (TLC) chromatographic procedures to study their physicochemical and biological properties. The results were used to identify the substances isolated. The preliminary data allowed us to identify the components X, A, and B as the previously described compounds undecylprodigiosin, anisomycin, and copiamycin, respectively, whereas component C is a natural compound, which probably has never been described.     

New antibiotics produced by Bacillus subtilis strains

Two Bacillus subtilis strains isolated from the fruiting body of a basidiomycete fungus Pholiota squarrosa exhibited a broad range of antibacterial activity, including those against methicillin-resistant Staphylococcus aureus INA 00761 (MRSA) and Leuconostoc mesenteroides VKPM B-4177 resistant to glycopeptide antibiotics, as well as antifungal activity. The strains were identified as belonging to the “B. subtilis” complex based on their morphological and physiological characteristics, as well as by sequencing the 16S rRNA gene fragments. Both strains (INA 01085 and INA 01086) produced insignificant amounts of polyene antibiotics (hexaene and pentaene, respectively). Strain INA 01086 also produced a cyclic polypeptide antibiotic containing Asp, Gly, Leu, Pro, Tyr, Thr, Trp, and Phe, while the antibiotic of strain INA 01085 contained, apart from these, two unidentified nonproteinaceous amino acids. Both polypeptide antibiotics were new compounds efficient against gram-positive bacteria and able to override the natural bacterial antibiotic resistance.     

Dynamic instabilities in microtubule cytoskeleton. A phase diagram

Instabilities in the growth and depolymerization of microtubules are considered in the framework of self-organization theory. An extended reaction-diffusion model for the microtubule dynamics has been formulated. A phase diagram of microtubule cytoskeleton has been constructed, which determines the regions of stability for steady and nonstationary solutions of the model. It is shown that the instabilities in microtubule dynamics result from kinetic nonequilibrium phase transitions. On the basis of phase diagram structure, a general classification of the microtubule cytostatic regulatory factors is suggested. The problem of mutual amplification of the activity of cytostatic agents is discussed.     

Isolation and evaluation of the structure of the new anthracycline antibiotics rubomycins F and H]

The rubomycin complex produced by Streptomyces coeruleorubidus 4-157 was studied and the two novel anthracyclines i.e. rubomycins F and H were isolated. The study of the physicochemical properties of the novel antibiotics in comparison with rubomycin C (daunomycin) and the specially prepared 3'-N-carbmethoxyrubomycin C showed that rubomycin F was 3'-N-carbethoxydaunomycin and rubomycin H was 3'-N-carbmethoxydaunomycin. Therefore, rubomycins F and H are novel representatives of natural anthracyclines undescribed previously.     

New amino acid from the antibiotic, ristomycin A]

A new amino acid E was isolated from a mixture of the products of the reductive hydrolysis of ristomycin A 57% HJ in the presence of red phosphorus. Its characterization was performed. The new amino acid was formed as a result of reductive dehydration of the respective beta-oxyamino acid present in the native antibiotic and being completely destroyed during general acid or alkaline hydrolysis.     

IGFBP-4 Proteolysis by PAPP-A in a Primary Culture of Rat Neonatal Cardiomyocytes under Normal and Hypertrophic Conditions

Biochemistry (Moscow) - Cardiovascular diseases (CVD) are among the leading causes of death and disability worldwide. Pregnancy-associated plasma protein-A (PAPP-A) is a matrix metalloprotease...