AA ConservationWe determined for ea

AA Conservation
We determined for each AA the 6 pairwise differences
of frequencies between the orthologs in human, chimp,
cow, and mouse. The sum of the 6 pairwise differences
was considered a measure of the quantity of conservation
of one protein between these 4 species for each AA
individually. When we considered a group of more than
one protein, the measure became the median of all the
measures found for each protein individually. We used
this approach on the 4 groups in milk (α-LA, caseins,
lactoferrin, and nonmilk proteins). We compared these
values with those calculated for the nonmilk proteins.
We used the Mann-Whitney test on the median of the
milk group and the nonmilk group to assess significance.
Here, the problem of multiple testing, arising from the
use of 20 AA, was corrected for using the Bonferroni
correction.