A non-statistical approach to protein mutational variability.

The non-statistical, non-Markovian model of protein mutational variability is described. There are presented the essential features of the algorithm of genetic semihomology and some examples of its application. The results of genetic semihomology approach are compared with the results obtained by using statistical algorithms and matrices which are assumed in widely used programs such as ClustalW, FASTA, MultAlin and BLAST. The aim of the new algorithm elaboration is to improve the accuracy of the results of protein sequence comparison, avoid the wrong assumptions and misinterpretation of the results, and increase the amount of information available from such study.