1. You are a top-notch biochemist who has to isolate a polypeptide from deadly spider venom. Unfortunately,...
Question:
1. You are a top-notch biochemist who has to isolate a polypeptide from deadly spider venom. Unfortunately, your lab is poor and you cannot afford an amino acid sequencer. However, you are capable of going “old-school” and you obtain the following data:
(1) Amino acid composition: 2 Lys, Gly, Met, Phe, His, Ser, Glu;
(2) Treatment with chymotrypsin yielded a dipeptide and a hexapeptide;
(3) Treatment with CNBr had no effect;
(4) Treatment with trypsin yielded a tripeptide, a tetrapeptide, and free Met;
(5) Treatment with dansyl chloride yields dansyl-Ser; and
(6) Treatment with S. protease yielded a pentapeptide and tripeptide with no charge at pH 5.
What is the sequence of the polypeptide?
2. (a) Using the first codon given for each amino acid in the Genetic Code, write the base sequence of mRNA that would translate the synthesis of the following pentapeptide:
Arg-Ile-Cys-Tyr-Val
(b) What base sequence in the DNA sense strand would correspond with this mRNA?
(c) What anticodons would appear in the tRNAs involved in the pentapeptide synthesis?