Prion diseases are neurodegenerative disorders affecting mammals with a diverse etiology. Although rare, most of the cases occur spontaneously in humans, with a minority being inherited or acquired by infection. Prion disease in ruminants such as sheep, goat, and deer are relatively frequent and likely feed borne [1] or environmentally transmitted [2]. The confirmed zoonotic potential of bovine...

background human immunodeficiency virus (hiv)-1 infection is one of the most important infectious diseases in iran, and common isolates belong to the new crf35_ad subtypes. the gp120 protein, which is located on the surface of the hiv envelope, plays a role in entrance into host cells and immune responses. as there isn’t any clear analysis of the envelope protein of iranian isolates regarding p...

Deletions of highly, but not entirely, homologous intragenic sequence repeats result in amino acid sequence and conformational changes in the M proteins of spontaneous M protein-size variants of group A streptococci. To determine if antigenic changes occurred as a result of these deletion mutations, monoclonal and polyclonal antibodies with defined epitopes were used in competition assays. Comp...

GLUT1 facilitates the down-gradient translocation of D-glucose across cell membrane in mammals. XylE, an Escherichia coli homolog of GLUT1, utilizes proton gradient as an energy source to drive uphill D-xylose transport. Previous studies of XylE and GLUT1 suggest that the variation between an acidic residue (Asp27 in XylE) and a neutral one (Asn29 in GLUT1) is a key element for their mechanisti...

The swarm of quasispecies that evolves in each HIV-1-infected individual represents a source of closely related Env protein variants that can be used to explore various aspects of HIV-1 biology. In this study, we made use of these variants to identify mutations that confer sensitivity and resistance to the broadly neutralizing antibodies found in the sera of selected HIV-1-infected individuals....

Essential physics associated with the conformational behavior of a linear semiflexible homopolymer chain have been derived from a model of directed self avoiding walk (DSAW) on a two dimensional rectangular lattice. The DSAW model has been solved analytically to study phase transitions occurring in the polymer chain and exact values of conformational properties and transition points have been r...

The linear, sulfated polysaccharide heparan sulfate occupies a pivotal position in intercellular signalling events, interacting with numerous proteins on the cell surface and in the extracellular matrix. Its complex sequences suggest high potential information content but, despite extensive efforts, a clear relationship between its substitution pattern and biological activity remains elusive. T...

Thermal conformational changes in human serum albumin (HSA) in present with a 10 mM phosphate buffer, at pH=7 have been investigated via circular dichroism (CD) and UV spectroscopic methods. The results indicate that temperature in a range of 25oC to 55oC could induce a reversible conformational change in the structure of HSA. The HSA phase transition corresponds to the physiological and patho...

Background: Immunoglobulins are a group of proteins have important role in defense against microorganisms. Human immunoglobulins are divided into five classes: IgA, IgM, IgD, IgE and IgG. Immunoglobulin G (IgG) is the highest abundant antibody in serum and extravascular fluids. The extent of serum IgG is related to severity of several diseases such as infections, so IgG has great diagnostic wor...

Conformational analysis of the experimentally recorded IR absorption spectra propanol in a gaseous state and low-temperature argon matrix at 20 K 35 was carried out for different spectral ranges. It showed that conformational composition samples gas isolation is different. In propanol, Gt conformers predominate, while most energetically favorable form Tg conformer, which prevails percentage bot...