Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Protein mass spectrometry wikipedia , lookup
Protein–protein interaction wikipedia , lookup
Western blot wikipedia , lookup
Intrinsically disordered proteins wikipedia , lookup
List of types of proteins wikipedia , lookup
Cooperative binding wikipedia , lookup
Protein moonlighting wikipedia , lookup
Degradomics wikipedia , lookup
Enzymes: Regulatory Regulatory enzymes In a metabolic pathway, which utilizes numerous enzymes, a regulatory enzyme sets the rate of the overall sequence because it catalyzes the slowest, rate-limiting reaction Characteristics of regulatory enzymes 1. 2. 3. 4. Enzymes: Regulatory Allosteric enzymes Involve reversible noncovalent binding of regulatory compounds called allosteric modulators Binding of modulators can be ___________ or ___________ Binding of modulator causes ____________________changes catalytic regulatory Enzymes: Regulatory - Allosteric enzyme Aspartate transcarbamoylase (ATCase) Feedback control by production of end product of pathway Allosteric inhibition - CTP inhibits aspartate transcarbamoylase by binding to a regulatory site (not an active site) Enzymes: Regulatory - Binding proteins Trypsin can be bound by trypsin inhibitor (BPTI) and inactivated Protease inhibitors are common in nature ~10% of blood plasma proteins are protease inhibitors A mutant of one protease inhibitor causes emphysema Enzymes: Regulatory - Reversible covalent modification Enzymes: Regulatory - Reversible covalent modification Methylation - involved in chemotaxis in bacteria ADP-ribosylation -involved in bacterial nitrogen fixation Examples: Diphtheria toxin and cholera toxin D toxin acts on and inhibits EF-2 (protein biosynthesis) C toxin acts on signaling protein (loss of body fluids - death) Phosphorylation - 1/3 to 1/2 of all euk. proteins are phosphorylated Enzymes: Regulatory - proteolytic activation Zymogen - inactive precursor (proteases) many proteases activated this way, activation is irreversible Proproteins/proenzymes - inactive precursor (other proteins) procollagen blood clotting system