Polar zippers: Their role in human disease

Glutamine repeats as polar zippers: their possible role in inherited neurodegenerative diseases.

Four inherited neurodegenerative diseases are linked to abnormally expanded repeats of glutamine residues in the affected proteins. Molecular modeling followed by optical, electron, and x-ray diffraction studies of a synthetic poly(L-glutamine) shows that it forms beta-sheets strongly held together by hydrogen bonds. Glutamine repeats may function as polar zippers, for example, by joining speci...

Biology of TH17 Lymphocytes, their Cytokines and Role in Disease

T lymphocytes that are involved in cellular mediated immunity include two types known as TCD8+ (Cytotoxic T lymphocytes) and TCD4+ (helper T lymphocytes). TCD4+ has four main subtypes, including TH1, TH2, TH17, and Treg Lymphocytes.TH17 lymphocytes play a role in defense against microbes that TH1 and TH2 lymphocytes have not the ability to respond to them. The most important cytokines, which ar...

Interhelical hydrogen bonds and spatial motifs in membrane proteins: polar clamps and serine zippers.

Polar and ionizable amino acid residues are frequently found in the transmembrane (TM) regions of membrane proteins. In this study, we show that they help to form extensive hydrogen bond connections between TM helices. We find that almost all TM helices have interhelical hydrogen bonding. In addition, we find that a pair of contacting TM helices is packed tighter when there are interhelical hyd...

Halogens and their role in polar boundary-layer ozone depletion

During springtime in the polar regions, unique photochemistry converts inert halide salt ions (e.g. Br) into reactive halogen species (e.g. Br atoms and BrO) that deplete ozone in the boundary layer to near zero levels. Since their discovery in the late 1980s, research on ozone depletion events (ODEs) has made great advances; however many key processes remain poorly understood. In this article ...

Archaea and their potential role in human disease.