Transcript Proteins
Proteins Proteins What are they? What are some examples of proteins? Worker molecules that do jobs in your body Hemoglobin – in your blood cells for carrying oxygen to your muscles Amylase – in your saliva for breaking down your food Myosin – in your muscles to make them contract Kinesin – in your cells to help transport big molecules around What are proteins made of? Amino acids What are these amino acids things?!? Essential amino acids Find the amino acid! Valine Hydrophobic Small Where Inside! am I? Find the amino acid! Lysine Positive charge Large Where am I? Outside! Find the amino acid! Tryptophan Hydrophobic Large Where Inside! am I? Protein Folding Amino acids hooked end-to-end like beads on a necklace Twisted and folded into the their final shape, which allows them to do their jobs Why do we care about folding anyway? Understanding diseases We think some diseases are caused by proteins getting messed up during folding. Can you think up some examples? Alzheimer’s disease Mad cow disease Parkinson’s disease Huntington’s disease Designing proteins to cure diseases How does folding work? Stable is better! Don’t let the amino acids bang into each other Smaller (more compact) is better Oil doesn’t mix with water Hydrogen bonds (like magnets) and sulfur-sulfur bonds (like superglue) help make it stronger How do we figure out how proteins fold? Give a BIG, POWERFUL computer the amino acid sequence of a protein Then wait, and wait, and wait, and wait…. Anton, a special computer designed to solve these problems, took 100 days to simulate 1 millisecond of folding How long would it take to Anton to simulate 1/10 of a second? 27 years Why is this hard? VERY,VERY large number of “poses” of protein ~10143 poses of single protein Only ~1081 atoms in the universe Proteins fold in << 1 second Bigger proteins don’t take much longer to fold, but are much harder to simulate So… Must be rules that let proteins find correct pose quickly Can’t test every pose, so have to be clever What is Foldit? Computer game developed at by computer scientists at University of Washington (in Seattle) Big idea: humans are good at using intuition to solve puzzles Success! Foldit players helped figure out the structure of a protein related to AIDS, which scientists had been trying to figure out for 15 years! The structure can now be used to help create new medicines for AIDS Foldit players figured out (on their own) state-of-the-art algorithms Some Foldit players are better than the scientists who made the game. They were invited to Seattle so that the scientists could learn their strategies. All sorts of people play Foldit. Maybe you can help with the next breakthrough in protein structure!