Metalloprotein

A metalloprotein is a protein that contains one or more metals, without need to be catalytically active. The metal ions in these proteins is critical for the function, structure and / or stability. Catalytically active metalloproteins are called metalloenzymes ( see there). They play a key role in biological processes, which are among the most complex and most importantly, occur in nature. Foremost among these are primarily photosynthesis, respiration ( respiration ), the molecular weight reduction of oxygen, the oxidation of water and nitrogen fixation. Metalloproteins account for almost half of all naturally occurring proteins, which underlines their importance.

Importance for medicine

Metalloproteins play a significant role both in countless physiological as well as pathological processes. They therefore represent a possible target for therapeutic intervention with drugs represents a good example of the great medical potential of metalloproteins are the branched into at least 54 families, " clans " of metalloproteases. In the early 1980s, selective inhibitors ( inhibitors) of the so-called angiotensin converting enzyme metalloproteinase family M2 were introduced into clinical practice for the treatment of hypertension (high blood pressure). These inhibitors prevent the formation of angiotensin II, which because of the role of this molecule in the maintenance of blood pressure, blood pressure reduction has resulted. More recent clinical trials examined - but so far with little success - members of the metalloproteinase family M10 ( with the matrix metalloproteinases MMP) on their therapeutic potential in terms of such diverse diseases such as cancer or arthritis, and members of the M12 family. The latter includes the group of Adama Lysine, including with the so-called TNF convertase ADAM17, which play a role in inflammatory ( inflammatory ) disease. Larger potential may have the MMP9 and MMP12 matrix metalloproteinases: You seem a key role in chronic obstructive pulmonary disease ( COPD) to play, but could be shown in a preclinical animal model that inhibition of these proteins is effective in COPD. A directed against these metalloproteins active ingredient of the pharmaceutical company AstraZeneca is currently (as of 2009) in a clinical trial, phase II

Examples

• Concanavalin A contains calcium and manganese and specifically binds certain types of sugars but without catalyze reactions. Without these metals, the sugar binding does not work.
• Calcium binds to calmodulin, which is then specific enzymes by protein-protein interaction is activated, this example illustrates the importance of calcium in the signal processing in the cell.
• Vanadium is enriched by certain sea squirts. This is made possible by vanadium -binding proteins, so-called Vanabine that are likely to play a role in the transport of oxygen these organisms.
• Ribonucleotide reductase comprising an iron complex which stabilizes an adjacent radical.
• Kupferchaperon superoxide dismutase ( engl. "copper chaperone for superoxide dismutase, CCS " ) is a ubiquitous protein, superoxide dismutase (SOD ) activated by specific protein-protein interaction by a copper CCS is transferred to SOD. When superoxide dismutase is a very important antioxidant for intracellular defense against oxygen free radicals, which may be for the development of dementia responsible.