Yabuki M, Fukui S
J Bacteriol. 1970 Oct;104(1):138-44. doi: 10.1128/jb.104.1.138-144.1970.
Mycelial cell wall of Aspergillus oryzae M-13 grown in an alpha-amylase-forming medium could not bind alpha-amylase (Taka-amylase A, EC 3.2.1.1). However, by treatment with 1.0 n NaOH at 100 C for 30 min, the wall gained the ability to bind alpha-amylase. This phenomenon was caused by removal of a factor (designated as masking factor) which masked the binding site for alpha-amylase. The masking factor was purified as a preparation giving a single peak in both ultracentrifugation (1.6S) and by gel electrophoresis (M(BPB), 1.0). Approximately 20 mug of the purified factor, bound to 10 mg of the alkali-treated mycelial cell wall, prevented the binding of approximately 100 mug of alpha-amylase or released approximately 100 mug of alpha-amylase which previously was bound to the alkali-treated wall. These findings indicate that the factor has much higher affinity than alpha-amylase for the binding site on the mycelial wall. The masking factor was inducibly formed accompanying the secretion of alpha-amylase.
在产α-淀粉酶培养基中生长的米曲霉M-13的菌丝细胞壁不能结合α-淀粉酶（高峰淀粉酶A，EC 3.2.1.1）。然而，通过在100℃用1.0 N NaOH处理30分钟，该细胞壁获得了结合α-淀粉酶的能力。这种现象是由于去除了一种掩盖α-淀粉酶结合位点的因子（称为掩盖因子）所致。该掩盖因子被纯化，其在超速离心（1.6S）和凝胶电泳（M（BPB），1.0）中均给出单一峰。约20μg纯化因子与10mg碱处理的菌丝细胞壁结合，可阻止约100μgα-淀粉酶的结合或释放约100μg先前结合在碱处理壁上的α-淀粉酶。这些发现表明，该因子对菌丝壁上的结合位点的亲和力比α-淀粉酶高得多。掩盖因子是伴随α-淀粉酶的分泌而诱导形成的。
