Question
Hypothetical integral membrane protein 221 amino acid residues in length with Consider four 1) (5 pts) a-helices. Residues 1-2[ are known to be entirely hydrophobic. Residues 22-80 and [25-201 form transmembrane two distinct intracellular globular domains exposed to the aqueous environment of the cytoplasm. Residues 99-104 fOrm an extracellular loop. Sketch plausible hydropathy plot for the hypothetical protein:
hypothetical integral membrane protein 221 amino acid residues in length with Consider four 1) (5 pts) a-helices. Residues 1-2[ are known to be entirely hydrophobic. Residues 22-80 and [25-201 form transmembrane two distinct intracellular globular domains exposed to the aqueous environment of the cytoplasm. Residues 99-104 fOrm an extracellular loop. Sketch plausible hydropathy plot for the hypothetical protein:
Answers
Integral membrane proteins are anchored in lipid bilayers. Of the following four groups of amino acids-nonpolar, polar, charged/ acidic, charged/basic (see Figure 3.2)-which would likely be found in the portion that crosses the lipid bilayer? Explain your reasoning.
Mhm. Remembering spending? Yeah. Memory spending. Alpha. Mhm. Okay. Hey, lucious are also the most common building most common protein structure. Mhm. Yeah. Element element dead closest. Mhm. Biological membrane. Yeah. Yeah. Okay. Mhm. Mhm. Yeah. Trans membrane 13. Yes. It's beautiful. Okay. It is presumed the Costa helical structure. Yeah. Yeah. Can satisfy all back home. No. Yeah, hydrogen bond what? Internally? Right. Mhm. Leaving no polar group. Mhm. Yeah. Mhm. Okay, exposed to the membrane. If the side chains mhm. Are hydrophobic. Yes. Mm hmm. Yeah. With the hydrophobic side chains indirect mm. With hydrophobic. Okay. Yeah. Yeah lipid lipid tales. Yeah.
I dropped the plot analysis helps us identify the regions of a poly peptide sequence that they're hydrophobic or high. The feeling this plot can help us understand structure or high protein. So did we can determine you far protein of interest is member and associate it or not, If we look at Hydra Apathy plot over here on the Y axis, we have high drop in the index that tells us the degree off hydrophobic city or Haider Felicity on the X axis, we have avenue acid sequence that we are analyzing before Hydra. Pretty blot analysis reveals a single prominent hydrophobic peak like we see over here. That could be a sign that our protein he is a membrane associated protein. This membrane associated protein has Onley one drugs membrane segment. This trance member in segment is associate it with our lipid membrane and it corresponds to our hydrophobic peak On our high dropped the flock analysis. However, this hydrophobic peak he's not a definite proof that are protein of interest is member in ISOC. It can also be eight globular protein, globular proteins, higher solly bill protein that are Spiric in shape and they have a specific tertiary structure. Dear Structure consists of a hydrophobic core surrounded with a hydro feel lik external surface This hydro Felix external surface interact with water So are globular protein is soluble in water but it has a hydrophobic segment. This hydrophobic core corresponds back to our hydrophobic peak. On our adopted plot analysis, this is example that even soluble proteins may have highly non polar regions and this explains why are high drop? A three block analysis can sometimes be misleading. That are protein of interest is member unassociated, but it actually is not.
For this question. We're looking at a picture in the textbook Were being given a trans membrane protein and we can see the hydrophobic segments passing through the membrane of the hydro Felix segments exposed what would be the effects of converting the first hydrophobic segments to a hydrophobic one. So the initial response is going to be it will no longer us remembering because it will no longer be hydrophobic. And we're going to sketch what it now looks like. So we have Here we go here is our bi layer. And if we compare this to the textbook, I'm going to start at the beginning. We're going to have our change. And instead of starting down here like we're going from a loop here, too, just skipping that loop entirely and then continuing on as usual has to a minute as there we go. This is it's probably not not this long. There we go, and I'm going to label the regions to make this a little bit easier. The part that we have changed is going to be here services here in the textbook. And so we've got one. We've got two three for five and six So all of all of these match up to the example textbook. The only one that has changed is its first one, which has now moved to the other side of the membrane because it's not passing through anymore.
If we clone the gene of a specific protein, let's say theory. Throw site protein, which we're guessing is a membrane protein. And no, the amino acid sequence, which is determined by the genes nucleotide sequence. Then we can determine the protein is in fact, an integral protein. We do this by creating a hydro path. The plot, which indicates whether potential trans membrane protein exists. If there are 20 or greater than 20 residues, then we can estimate that there is a trans membrane present. Yeah, if we know the protein is an integral protein that consists of a trans membrane segment, we can conduct a biochemical or chemical experiment, such as finding out of the protein intact. Every throw sites will react with the re agent that cannot go through a membrane and a specific will primary Amin's. If it goes through the memory, then we know the amino terminus is not on the inside of the cell, but on its outside