if anyone can help me with this, THANK YOU!! I Question 6 Y ou have been given a
ID: 199429 • Letter: I
Question
if anyone can help me with this, THANK YOU!! I
Question 6 Y ou have been given a pure unknown inflammatory protein and are trying to etermine its sequence. You perform the following reactions and purify various products. ou then perform amino acid analysis and sequencing on the peptides obtained Untortunately, you have very little starting material, so you can only sequence 4-5 residue of each peptide before you run out. Note: peptides shorter than 2 amino-acids long generally can't be sequenced. First you purify to a single peak by chromatography. Unfortunately the sequencing is iguous. You decide to react your pure protein with mercaptoethanol and iodoacetate, and find that you have TWO peptide chains, call them "A and "B". So you purify them separately by chromatography a. Why did you treat the protein with mercaptoethanol and iodoacetate? The following questions are only about peptide "A Using the fragments only below only, what is the sequence of Peptide A? Match this sequence with the AAA. Make a chart that shows amino acids seen in the AAA and those predicted by your sequence so far, from (b). Account for differences. Modify the sequence to fit the AAA data, as necessary Are you certain of the C-terminal amino acid? Why or why not? What technique could you use to determine it, if you weren't sure? b. c. d. Peptide "A Amino acid analysis (AAA): (C* means S-carboxymethylcysteine, the product of cysteine after the above treatment) After cleavage with trypsin, you purify two peptides. A1 A2 sequence (remember, only the first 4-5 are seen!) D-M-E-Q-R. S-c+-T-T-M. After cleavage with CNBr, you obtain three peptides Fragment sequence (remember, only the first 4-5 are seen!) I-I-T-T. E-Q-R-S-C D-M A2 A3Explanation / Answer
Answer
Chromatography: It is technique to separate the mixture solution using one stationary phase and another moving phase.While separation of protein mixture an ionic column as stationary phase is used which binds the opposite charge protein and other protein eluted from the column.
A) Treatment of protein with beta mercaptoethanol: It would removed all the disulphides bond which give tertiary structure to the protein.
Treatment with iodoacetate: It reacts with the amino acid (cysteine) add any functional group in a protein sequence.It prevent the protein to reformed the disulphides bond.
B) as given in the result the peptide sequence is C*-D-E-E-I-I-M-M-R-S-T-T-T-T
C) Trypsin treatment cleave the protein from carboxylate end at the lysin or arginine amino acid followed by proline. Then After the amino acid analysis the actual peptide sequence is D-M-E-Q-R and S-C*-T-T-M and remaining I-I—T-T and E-E-M
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.