Distribution of i-spaced amino acid pairs (DiSAAP) is presented as the statistics of
occurrence of pair of amino acids separated along the chain by i residues (i =
If a DiSAAP for particular amino acid or certain group of amino acids has to be
constructed, special indicator "X" should be chosen in the menu "Type of Task".
Consequently the raw of menus for selection X will appear. So, X will present a
particular amino acid (for example A or G or R etc) or group of amino acids (for example
hydrophobic (L,I,V,F,A,W) or charged (R, K, E, D) or any group desired).
If the indicator "XY" will be chosen in the menu " Type of Task", a DiSAAP for X and Y
amino acids , or two different groups of amino acids will be constructed. In the case of
indicator of "XY" two raw of menus for selection of X and Y will appear. X and Y present
a particular amino acid (for example A or G or R etc) or group of amino acids (for
example hydrophobic (L,I,V,F,A,W) or charged (R, K, E, D) or any group desired). X and Y
should be different. In general, statistics built for XY pair is distinguished from
statistics built for YX pair. The X should be chosen from upper raw of menus and Y from
Statistics has presented by observed frequencies fi ( relied on the DBAASP
data), average value of expected frequencies Fi and their standard deviation σi
(i=0,1,2,...,10). Expected frequencies are estimated for random sequences
generated by random shuffling of sequences of considered set of peptides.
Shuffling is repeated 500 times to assess average and standard deviation.