Enzyme bond cleavage site. Animation showing the molecular structure of the active site (grey) of the enzyme carboxypeptidase (pink). This enzyme cleaves peptide bonds. The molecule that the enzyme is acting on (the substrate) is partially shown inside this active site (or cleft). This molecule is a polypeptide chain. It is linked to the enzyme by five weak bonds (glowing red). Also shown is the molecular structure of the attachment sites, with seven amino acids named in the structures: Tyr 248, Glu 270, Arg 71, Glu 72, His 196, His 69, and Arg 145. Tyr is tyrosine, Glu is glutamic acid, Arg is arginine, and His is histidine. The function of this enzyme is to separate the polypetide chain's terminal amino acid (top) from the rest of the polypeptide chain (extending down out of frame). It does this by cleaving the covalent bond indicated by the arrow (hydrolysis, addition of H2O, a water molecule, across the bond). The nearby attachment sites are the electronegative zinc centre (Zn) and the charged oxygen centre (O) that draw away the electrons of this bond, helping to initiate its rupture. The products of the reaction are shown at right, with the terminal amino acid at centre right and the rest of the polypeptide chain at far right. For this animation with labels, see K004/4315. | |
Licence : | Droits gérés |
Crédit : | Science Photo Library / Biocosmos / Francis Leroy & Michael Pierard |
Model Release : | Non requis |
Durée : | 7 Secondes |
Aspect ratio : | 16/9 |
Restrictions : | - |