BLOSUM

BLOSUM (BLOcks Substitution Matrix) is a tool used in biology to compare protein sequences. It helps determine how similar or different two proteins are by assigning scores to the likelihood of one amino acid (building block of proteins) replacing another over evolutionary time. These scores are based on analyzing small, conserved regions (blocks) of many related proteins. A higher score indicates a more likely, natural substitution, while a lower score suggests rarity or less similarity. BLOSUM matrices assist scientists in identifying evolutionary relationships and functional similarities between proteins.