|Endoproteases that contain proteolytic core domains and ATPase- containing regulatory domains. They are also called as endopeptidase or endoproteinase. Exopeptidase which break peptide bonds from their end-pieces. endopeptidases cannot break down peptides into monomers, while exopeptidases can break down proteins into monomers. The top open access journals are peer reviewed scholarly journals of Enzyme Engineering. The top open access journals are freely available on the public internet domain, allowing any end users to read, download, copy, distribute, prink, search or link to the full texts of the articles. These provide high quality, meticulously reviewed and rapid publication, to cater the insistent need of scientific community. These journals are indexed with all their citations noted. The top open access journals are indexed in MEDLINE, PUBMED, SCOPUS, COPERNICUS, CAS, EBSCO and ISI.