[A new method of producing biologically active nanocomplexes by non-covalent conjugation of proteins with viral particles].

Currently, a range of biologically active molecules have been attached to plant and bacterial viras nanoscaffolds, yielding stable nanoparticles that display multiple copies of the desired molecule. In this paper we propose a new method of non-covalent attachment of peptides to the surface of virios. We have demonstrated that this method is efficient in a model system that includes tobacco mosaic virus particles, synthetic polycation (quaternized poly(4-vinylpyridine) carrying ethyl ethyl pendant radicals) and polypeptide of interest. This principle of step-by-step binding to the surface of virions was used for electrostatic association with hydrophilic fragment of influenza virus haemagglutinin.

Oligomerization of the potato virus X 25-kD movement protein.

A 25-kD movement protein (25K protein) encoded by the first gene of the potexvirus Potato virus X triple gene block of transport genes is essential for the viral movement in infected plants. The 25K protein belongs to superfamily 1 of NTPase/helicases and exhibits in vitro RNA helicase, Mg2+-dependent NTPase, and RNA-binding activities. In the present work, the ability of 25K protein for homologous interactions was studied using the yeast two-hybrid system, protein chemical cross-linking in the presence of glutaraldehyde, far-Western blotting, and ultracentrifugation in sucrose density gradients. The 25K protein was shown to form homodimers and homooligomers. Sites of homologous protein-protein interactions were found in both the N- and C-terminal portions of the protein.

[Virions and membrane proteins of the potato X virus interact with microtubules and enables tubulin polymerization in vitro]. / Viriony i belok obolochki X-virusa kartofelia vzaimodeistvuiut s mikrotrubochkami i sposobstvuiut polimeriaztsii tubulina in vitro.

A study was made of the in vitro interactions of virions and the coat protein (CP) of the potato virus X (PVX) with microtubules (MT). Both virions and CP cosedimented with taxol-stabilized MT. In the presence of PVX CP, tubulin polymerized to produce structures resistant to chilling. Electron microscopy revealed the aberrant character of the resulting tubulin polymers (protofilaments and their sheets), which differed from MT assembled in the presence of cell MAP2. In contrast, PVX virions induced the assembly of morphologically normal MT sensitive to chilling. Virions were shown to compete with MAP2 for MT binding, suggesting an overlap for the MT sites interacting with MAP2 and with PVX virions. It was assumed that PVX virions interact with MT in vivo and that, consequently, cytoskeleton elements participate in intracellular compartmentalization of the PVX genome.

Matrix engineering.

Matrix engineering is a technology that utilizes hyaluronan (HA, hyaluronic acid) based matrices to control, direct or augment tissue regenerative processes. Hyaluronan and the concept of matrix engineering have become established tools in ophthalmic and orthopaedic medicine. The clinical indications for HA are limited by the physical properties and short residence time of the natural HA molecule. To expand and improve upon its current medical applications, a family of HA derivatives was prepared by chemical modification and cross-linking. Relative to the non-modified HA molecule, the hylan family of polymers provides more versatile physical forms, improved mechanical properties and an extended residence time. Hylan can also be used as a surface coating to improve blood compatibility. The chemical, physical and biological properties of hylans will be reviewed, focusing on the specific therapeutic indications they enable.