Key for 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 data of last
modification.
(b) MLH1_HUMAN
(c) Release 40, October 2001
ExPASy -> click SWISS-PROT and TrEMBL (under
Database) -> click SRS
-> hit Start Button -> select SWISS-PROT
and TrEMBL -> hit Continue Button
-> Choose AllText, type mlh1 on first line ->
Choose Organism, type human on second line
-> hit DO Query Button -> You will find 4
entries -> click on SWISS PROT:MLH1
HUMAN
2. Give its number of amino acids, molecular weight and theoretical pI.
click on ProtParam (under Tools at the buttom of the
page) -> hit SUBMIT Button
3. Calculate the total number of negatively charged residues and positively
charged residues.
Same as question 2.
4. Calculate its hydrophobicity (Kyte & Doolittle scale, window size 11,
Relative weight 60%).
click on ProtScale (under Tools at the buttom of the
page) -> choose Hphob. / Kyte & Doolittle
->
change window size and relative weight at the buttom
of the page -> hit Submit Button -> hit SUBMIT button
again
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.
(a) 33
click on PeptideMass (under Tools at the buttom of the
page) -> Select an enzyme : Trypsin (higher specificity) ->
choose 1000 under "Display the peptides with a mass
bigger than 1000 dalton" -> hit Perform
Button
PCL