▁Ly so zym es ▁active ▁site ▁bind s ▁the ▁pe pt id og ly can ▁mole c ule ▁in ▁the ▁prominent ▁c left ▁between ▁its ▁two ▁domains . ▁It ▁attacks ▁pe pt id og ly c ans ▁( found ▁in ▁the ▁cell ▁walls ▁of ▁b acter ia , ▁especially ▁Gram - pos itive ▁b acter ia ), ▁its ▁natural ▁substr ate , ▁between ▁N - ac et yl m ur am ic ▁acid ▁( NA M ) ▁and ▁the ▁fourth ▁carbon ▁atom ▁of ▁N - ac et yl gl uc os am ine ▁( NA G ). ▁ ▁Sh orter ▁sac char ides ▁like ▁t et ras ac char ide ▁have ▁also ▁shown ▁to ▁be ▁vi able ▁substr ates ▁but ▁via ▁an ▁intermediate ▁with ▁a ▁longer ▁chain . ▁Ch it in ▁has ▁also ▁been ▁shown ▁to ▁be ▁a ▁vi able ▁ly so zym e ▁substr ate . ▁Art ific ial ▁substr ates ▁have ▁also ▁been ▁developed ▁and ▁used ▁in ▁ly so zym e . ▁ ▁Mechan ism ▁ ▁Phill ips ▁ ▁The ▁Phill ips ▁Mechan ism ▁proposed ▁that ▁the ▁en zym e ' s ▁catal yt ic ▁power ▁came ▁from ▁both ▁ster ic ▁stra in ▁on ▁the ▁bound ▁substr ate ▁and ▁electro static ▁stabil ization ▁of ▁an ▁ox o - car ben ium ▁intermediate . ▁From ▁X - ray ▁cry stal log raph ic ▁data , ▁Phill ips ▁proposed ▁the ▁active ▁site ▁of ▁the ▁en zym e , ▁where ▁a ▁hex as ac char ide ▁bind s . ▁The ▁ly so zym e