The mode of hydrolysis of a glycan portion of Micrococcus lysodeikticus cell walls by endo-N-acetylglucosaminidase or endo-N-acetylmuramidase isolated from crude barley beta-amylase.

Micrococcus lysodeikticus cell walls were digested with a pI 6.8 endo-N-acetylglucosaminidase or a pI 9.5 endo-N-acetylmuramidase. The digests were further treated with a N-acetylmuramyl-L-alanine amidase of Flavobacterium L-11 enzyme to remove the peptide portion. The products were fractionated by gel filtration and ion-exchange chromatography, and the glycan portion of fractions were analyzed for their average amino sugar chain lengths. The following results were obtained. 1. The glycan portion of the main products in the pI 6.8 enzyme digest consisted of (-N-acetylmuramic acid-N-acetyl-glucosamine-)2-3. 2. The glycan moiety of the pI 9.5 enzyme digest was mainly composed of (-N-acetylglucosamine-N-acetylmuramic acid-)3-4. 3. The glycosidic linkages around the muramic acid 6-phosphate residues which linked to a special structure through a phosphodiester bond were rather refractory to the glycosidase action of both pI 6.8 and 9.5 enzymes.