Visual science

Crystal structure of fibrinogen. The central nodule, formed by the N-terminal portions of all six chains, is connected to the distal β- and γ-nodules formed by the C-terminal portions of the Bβ and γ chains, respectively, by triple-helical coiled-coils, each formed by the middle portions of the Aα, Bβ and γ chains.

The two aminoacids at the botton (the distal histidine and the distal valine) touch the heme but are not bounded to it. The proximal histidine is the principal path for comunicatión between the heme and the rest of the molecule. It forms a chemical bond with the heme iron. In oxy state hemoglobin the iron is aligned in the center of hemo group. In the deoxy form the iron is displaced 0.5 amstrong off the heme center approaching to the proximal histidine, which is moved in the same direction, offseting it. Which leads a conformational change which is transmited over the entire molecule.

CETP (cholesteryl ester-transfer protein) is essential for neutral lipid transfer between HDL (high-density lipoprotein) and LDL (low-density lipoprotein) and plays a critical role in the reverse cholesterol transfer pathway.

The structure of CETP reveals a 60-A-log tunnel filled with two hydorphobic cholesteryl esters and plugged by an amphiphilic phosphatidylcholine at eatch end. The two tunnel openings are large enough to allow lipid access, which is aided by a flexible helix and possibly also by a mobile flap. The curvature of the concave surface of CETP matches the radius of curvature of HDL particles, and potential conformational changes may occur to accommodate larger lipoprotein particles. Point mutations blocking the middle of the tunnel abolish lipid-transfer activities, suggesting that neutral lipids pass through this continuous tunnel.

Glycated hemoglobin bound to four oxygen molecules.

Cover: The annotation and curation of ribosomal RNA (rRNA) sequences. This cover is an abstract representation of the annotation and curation process for rRNA sequences. On the left, a ribosome is shown in the process of translating a blue strand of mRNA. On the right, a cellular regulatory network is depicted, with nodes that are dependent on ribosome function shown in red. The wisps of smoke connecting the two sides of the image represent the computerized annotation and curation process for the positive and negative strands of DNA that code for rRNA. The two interlocking arrows at the top represent DNA coding regions for rRNA subunits, which often go unannotated or corrected by curators. The three interlocking arrows at the bottom represent possible open reading frames (ORFs) that could code for regulatory polypeptides at the same time that they code for rRNA. Dual coding is a rare but not unreported phenomenon that is frequently misannotated, particularly for rRNA. The misannotation of dual coding regions for rRNA and polypeptides not only frustrates drug discovery, but can lead to a false positive rate approaching 90% in metatranscriptomic studies, since they attempt to infer protein function from RNA transcripts. Cover Art designed and produced by: Ramón Andrade, 3Dciencia, http://3dciencia.com/. For further information, please see the article by H. J. Tripp et al., Nucleic Acids Res., 2011, 39, 8792–8802.

Human prostate-specific antigen (PSA or KLK3) is an important marker for the diagnosis and management of prostate cancer. This is an androgen-regulated glycoprotein of the kallikrein-related protease family secreted by prostatic epithelial cells. Its physiological function is to cleave semenogelins in the seminal coagulum and its enzymatic activity is strongly modulated by zinc ions.

Dendritric cell (green) is the nexus between the innate and adaptative immunity. Lymphocyte (yellow)

Influenza virus particle entering a cell in the respiratory tract.

Cancer Antibody response

Monoclonal antibody therapy is the use of monoclonal antibodies (or mAb) to specifically bind to target cells. This may then stimulate the patient's immune system to attack those cells. It is possible to create a mAb specific to almost any extracellular/ cell surface target, and thus there is a large amount of research and development currently being undergone to create monoclonals for numerous serious diseases (such as rheumatoid arthritis, multiple sclerosis and different types of cancers). There are a number of ways that mAbs can be used for therapy. For example: mAb therapy can be used to destroy malignant tumor cells and prevent tumor growth by blocking specific cell receptors.