Correlation between stability of a protein and its dipeptide composition: a novel approach for predicting in vivo stability of a protein from its primary sequence

Statistical analysis of 12 unstable and 32 stable proteins revealedthat there are certain dipeptides, the occurrence of which issignificantly different in the unstable proteins compared withthose in the stable ones. Based on the impact of these dipeptideson the unstable proteins over the stable ones, a weight valueof instability is assigned to each of the dipeptides. For agiven protein the summation of these weight values normalizedto the length of its sequence helps to distinguish between unstableand stable proteins. Results suggest that the in vivo instabilityof proteins is possibly determined by the order of certain aminoacids in its sequence. An attempt is made to correlate metabolicstability of proteins with features of their primary sequencewhere weight values of instability for a protein of known sequencecould thus be used as an index for predicting its stabilitycharacteristics.