Assignment 5

1. Search human MutL protein homolog 1, Mlh1, in SWISS-PROT database. Give its (a) accession number, (b) entry name and (b) release date of last modification.

accession number: P40692

entry name: MLH1_HUMAN

Release 40, October 2001

2. Give its number of amino acids, molecular weight and theoretical pI.

Length: 756 AA

Molecular weight: 84600.98 Da

theoretical pI: 5.51

3. Calculate the total number of negatively charged residues and positively charged residues

Total number of negatively charged residues (Asp + Glu): 104

 Total number of positively charged residues (Arg + Lys): 83

4. Calculate its hydrophobicity (Kyte & Doolittle scale, window size 11, Relative weight 60%).

5. Performe the trypsin (higher specificity) cleavage of the protein. (a) How many peptides will you get after cleavage? (b) Give the list of peptides with a mass bigger than 1000 dalton.

33 peptides(bigger than 1000 Da)