IIl. The following questions is based on t a peptide with a sequence: 1. Transla
ID: 543866 • Letter: I
Question
IIl. The following questions is based on t a peptide with a sequence: 1. Translate the single letter peptide sequence into three letter abbreviations(Spt) 2. If the peptide is subjected to hydrolysis by protease of cleavage point at arg (C) indicate the peptide bond the will be broken (Spt) 3. Draw the chemical structure of the shorter or shortest fragment(s) (Spt) If the pKa of the ionizable groups are the same as those listed for the corresponding amino acid, calculate the pl of the peptide(10pt) 4.Explanation / Answer
1) Cys Ala Arg Asp Ser is the three letter code for the sequence CARDS.
Cys - cysteine -C , Ala - alanine - A , Arg - arginine - R, Asp - asparitic acid - D , Ser - serine - S
2)
Protease Arg C cleaves C terminus of arginine. Thus it cleaves the peptide bond between Arg and Asp.
An amino acid sequence starts from N- terminal and ends in C- terminal.
3)
Shortest fragment in these sequence is Alanine ,
NH2-CH (CH3)-COOH.