Nanobodies are a type of antibodies derived from camels, and are much smaller than traditional antibodies. Standard antibodies are giants by molecular standards, since each one is a conglomerate of two heavy protein chains and two light chains, intricately folded and garnished with elaborate sugars. Nanobodies, however, are relatively simple proteins about a tenth the size of human antibodies and just a few nanometers in length. After the discovery that camelidea (camels and llamas) possess fully functional antibodies that lack light chains, the nanobody technology was developed to exploit these smaller heavy-chain-only constructs. Nanobodies are being researched for multiple pharmaceutical applications and have potential for use in cancer and Alzheimer's Disease treatments.(1,2) Wikipedia does not yet have an article with this exact name. ... For other uses, see Camel (disambiguation). ... Wikipedia does not yet have an article with this exact name. ... When normal cells are damaged beyond repair, they are eliminated by apoptosis. ...

Traditional therapeutic monoclonal antibodies (MAbs) must be stored at near freezing temperatures to prevent their destruction. Antibodies are not suited for oral administration because they are digested quickly in the gut, and are not usually useful for treating diseases of the brain because they do not easily permeate the blood-brain barrier. Additionally, therapeutic antibodies are not well suited to target large tumors because they are held to the periphery of solid tumors. Many illnesses are thus unreachable by monoclonals, and patients who use MAb therapies must receive them by injection or infusion at a clinic. For certain conditions in which the traditional MAbs do not work well, and even for some in which they currently do, simpler, smaller proteins like nanobodies might perform better, be easier to make, easier to handle, easier to admister, and be more affordable. (2) Monoclonal antibodies (mAb) are antibodies that are identical because they were produced by one type of immune cell, all clones of a single parent cell. ... The blood-brain barrier (BBB) is a membrane that controls the passage of substances from the blood into the central nervous system. ...

In 1989 a group of biologists led by Raymond Hamers at the Free University that investigated an odd observation handed in as part of a student project on how dromedary camels (the one-humped, Arabian variety) and water buffalo fight off parasites. One of the tests for antibodies in the dromedary blood seemed to show an error: in addition to normal four-chain antibodies, it indicated the presence of simpler antibodies composed solely of a pair of heavy chains.

After several years of investigation, Hamers and his colleagues published their discovery in Nature in 1993. In dromedaries--and also in two-humped Asian camels and South American llamas--about half the antibodies circulating in the blood lack a light chain. Equally surprising, they found, these "incomplete" antibodies are able to grasp their targets just as firmly as normal antibodies do, with affinities for their targets virtually equal to a full antibody 10 times their size. Binomial name Lama glama (Linnaeus, 1758) The llama (Lama glama) is a large camelid that originated in North America and then later on moved on to South America. ...

These shortened proteins were also more chemically agile, able to engage targets--including the active sites of enzymes and clefts in cell membranes--too small to admit an antibody. Ribbon diagram of the enzyme TIM. TIM is catalytically perfect, meaning its conversion rate is limited, or nearly limited to its substrate diffusion rate. ...

Because nanobodies are so much smaller than antibodies and are not hydrophobes (as are standard human antibodies), they are more resistant to heat and pH, and may retain their activity as they pass through the gastrointestinal, raising the prospect of oral nanobody pills to treat inflammatory bowel disease, colon cancer and other disorders of the gut. (2) Hydrophobe (from the Greek (hydros) water and (phobos) fear) in chemistry refers to the physical property of a molecule that is repelled by water. ... In medicine, inflammatory bowel disease (IBD) is a group of inflammatory conditions of the large intestine and, in some cases, the small intestine. ... Diagram of the stomach, colon, and rectum Colorectal cancer includes cancerous growths in the colon, rectum and appendix. ...

External link

(1) *http://www.news-medical.net/?id=1477 (2) *http://www.nanobody.org

• Scientific American Magazine (August 2005 Issue) Nanobodies