Lin B K, Anderson J A
Department of Chemistry and Biochemistry, Texas Tech University, Lubbock 79409.
Arch Biochem Biophys. 1992 Feb 14;293(1):67-70. doi: 10.1016/0003-9861(92)90366-5.
Versiconal cyclase catalyzes the dehydration of versiconal to versicolorin B or versicolorin C [versicolorin B(C)]. The enzyme was purified from mycelia of Aspergillus parasiticus by DEAE-cellulose, hydroxylapatite, and Mono Q column chromatography. The protein contains two identical subunits of molecular weight 72,000 per molecule of native protein. The pI of the enzyme is 3.95. The pH activity curve had a broad maximum with a peak at 5.5. The Km and Vmax for versiconal at 30 degrees C and pH 6.0 are 3.1 microM and 0.15 mumol min-1mg-1, respectively. Most of the formation of versicolorin B(C) in the cell is attributed to the action of versiconal cyclase.
Versiconal环化酶催化Versiconal脱水生成Versicolorin B或Versicolorin C [Versicolorin B(C)]。该酶通过DEAE-纤维素、羟基磷灰石和Mono Q柱色谱从寄生曲霉的菌丝体中纯化得到。该蛋白质每个天然蛋白质分子含有两个分子量为72,000的相同亚基。该酶的pI为3.95。pH活性曲线在5.5处有一个宽峰，最大值出现在该点。在30℃和pH 6.0条件下，Versiconal的Km和Vmax分别为3.1 microM和0.15 mumol min-1mg-1。细胞中Versicolorin B(C)的形成大多归因于Versiconal环化酶的作用。
