Howard L V, Gooder H
J Bacteriol. 1974 Feb;117(2):796-804. doi: 10.1128/jb.117.2.796-804.1974.
A Streptococcus (Diplococcus) pneumoniae autolysin, partially purified from cellular autolysates, was optimally active at pH 7.0 and was stimulated by monovalent cations. Addition of autolysin to walls resulted in the appearance of only N-terminal l-alanine, whereas no glycosidase activity was observed. Walls which had been solubilized by autolysin were separated by gel filtration into a low-molecular-weight peptide containing amino acids in the same ratios found in intact walls and a high molecular fraction containing the amino acid-deficient peptidoglycan backbone. Thus, the major activity is an N-acetylmuramyl-l-alanine amidase. In addition, walls undergoing spontaneous lysis revealed no glycosidase activity but showed an increase in only N-terminal alanine. Autolysin, which was bound to walls in saline, was almost completely removed when walls were washed in distilled water, and all of the activity was recovered in the water wash fluid.
一种从细胞自溶物中部分纯化得到的肺炎链球菌（双球菌）自溶素，在pH 7.0时活性最佳，并受到单价阳离子的刺激。将自溶素添加到细胞壁中仅产生N端的L-丙氨酸，未观察到糖苷酶活性。经自溶素溶解的细胞壁通过凝胶过滤分离成一个低分子量肽段，其氨基酸比例与完整细胞壁中的相同，以及一个高分子量部分，包含缺乏氨基酸的肽聚糖主链。因此，主要活性是N-乙酰胞壁酰-L-丙氨酸酰胺酶。此外，发生自发裂解的细胞壁未显示糖苷酶活性，但仅N端丙氨酸有所增加。在盐溶液中与细胞壁结合的自溶素，当细胞壁用蒸馏水洗涤时几乎完全被去除，并且所有活性都在水洗液中恢复。
