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Random protease digestion of a certain peptide hormone (length=20 amino acyl res

ID: 196235 • Letter: R

Question

Random protease digestion of a certain peptide hormone (length=20 amino acyl residues) revealed the following peptide fragments:

TRP-GLY-LYS-PRO

VAL-GLY-LYS-LYS

SER-MET-GLU-HIS

PRO-ILE

ARG-ARG-PRO-ILE

ARG-TRP-GLY-LYS

PHE-ARG-TRP-GLY

LYS-ARG-ARG-PRO

LYS-LYS-ARG-ARG

PRO-VAL-GLY-LYS

LYS-PRO-VAL-GLY

MET-TYR-SER

MET-TYR

MET-TYR-SER-MET

MET-GLU-HIS-PHE

TRP-GLY-LYS-PRO

among others. What is the likely sequence of the hormone?

TRP-GLY-LYS-PRO

VAL-GLY-LYS-LYS

SER-MET-GLU-HIS

PRO-ILE

ARG-ARG-PRO-ILE

ARG-TRP-GLY-LYS

PHE-ARG-TRP-GLY

LYS-ARG-ARG-PRO

LYS-LYS-ARG-ARG

PRO-VAL-GLY-LYS

LYS-PRO-VAL-GLY

MET-TYR-SER

MET-TYR

MET-TYR-SER-MET

MET-GLU-HIS-PHE

TRP-GLY-LYS-PRO

Explanation / Answer

Considering that the sequence of the peptide fragments in in continuation in the boxes presented above, the mRNA sequence of the hormone can be deduced using the amino acid codon table. Presented here are the sequence for the amino acids (there might be different combinations possible as a singly amino acid has different codons).

TRP-GLY-LYS-PRO- UGGGGUAAACCU

VAL-GLY-LYS-LYS- GUUGGUAAAAAA

SER-MET-GLU-HIS- UCUAUGGAACAU

PRO-ILE- CCUAUU

ARG-ARG-PRO-ILE- AGAAGACCUAUU

ARG-TRP-GLY-LYS- AGAUGGGGUAAA

PHE-ARG-TRP-GLY- UUUAGAUGGGGU

LYS-ARG-ARG-PRO- AAAAGAAGACCU

LYS-LYS-ARG-ARG- AAAAAAAGAAGA

PRO-VAL-GLY-LYS- CCUGUUGGUAAA

LYS-PRO-VAL-GLY- AAACCUGUUGGU

MET-TYR-SER- AUGUAUUCU

MET-TYR- AUGUAU

MET-TYR-SER-MET- AUGUAUUCUAUG

MET-GLU-HIS-PHE- AUGGAACAUUUU

TRP-GLY-LYS-PRO- UGGGGUAAACCU