« Back to Glossary Index

shape-shift. “Conformation” is often used to refer to one of several alternative shapes a protein can take. So, for example, a protein might exist in one shape when it’s not bound to a partner and then, upon binding to a partner it can undergo a conformational change (maybe clamping around the partner). Some proteins have “active” conformations where they’re ready to go perform whatever task they’re tasked with and “inactive” conformations, where they’re temporarily on hold. Sometimes conformational changes are regulated by phosphorylation (addition of a phopshoryl group). When proteins are phosphorylated, they now have a highly concentrated, bulky, charge -> this can cause the protein to change its conformation (e.g. maybe the negative charge is repulsive so the atoms around it try to “move away” – but because all the protein’s amino acids are linked together, changes in one can have a “ripple effect” with parts of the protein that have a more defined shape (structural domains) often moving as a group and more flexible “linker” regions serving as hinges. You can also have the opposite – if there are + charged amino acids around, they’ll be glad to hang out around the phosphate and can “clamp down” around it & oxygens in the phosphoryl group can hydrogen-bond (H-bond) with group(s) on the protein for a similar “clamping” effect. These conformational changes can activate or inactivate the proteins (e.g. they might bring the catalytic amino acids together to form an active site that wasn’t there before.