Sharma A, Padwal-Desai S R, Ninjoor V
Food Technology & Enzyme Engineering Division, Bhabha Atomic Research Centre, Bombay, India.
Biochem Biophys Res Commun. 1989 Mar 15;159(2):464-71. doi: 10.1016/0006-291x(89)90015-6.
When the distribution profile of hydrolases in mycelial homogenates and culture filtrates of A. parasiticus and A. flavus was examined, six hydrolytic enzymes viz. N-acetyl-beta-glucosaminidase, aryl sulfatase, alkaline proteinase, cathepsin B, cathepsin D and aminopeptidase were detected in homogenate. The culture filtrates were devoid of any activity of these enzymes. The enzyme levels varied with the stage of incubation. The most abundant fungal exopeptidase showing preference for basic amino acid naphthylamides seems to be an aminopeptidase B. Incorporation of CEPA, an ethylene generating compound, stimulated the amino peptidase activity in the mycelium but inhibited the enzyme in vitro. The enzyme was also inhibited by different aflatoxins to varying degree. While aminopeptidase B was located intracellularly, a non-dialysable, heat-stable inhibitor of the enzyme was found to be secreted in the culture filtrate. This peptide inhibitor was however ineffective on the other enzymes.
当检测寄生曲霉和黄曲霉的菌丝体匀浆及培养滤液中水解酶的分布情况时，在匀浆中检测到了六种水解酶，即N - 乙酰 - β - 葡糖胺酶、芳基硫酸酯酶、碱性蛋白酶、组织蛋白酶B、组织蛋白酶D和氨肽酶。培养滤液中未检测到这些酶的任何活性。酶水平随培养阶段而变化。对碱性氨基酸萘酰胺表现出偏好的最丰富的真菌外肽酶似乎是氨肽酶B。乙烯生成化合物CEPA的加入刺激了菌丝体中的氨肽酶活性，但在体外抑制了该酶。该酶也受到不同黄曲霉毒素不同程度的抑制。虽然氨肽酶B定位于细胞内，但发现一种不可透析、热稳定的该酶抑制剂分泌到了培养滤液中。然而，这种肽抑制剂对其他酶无效。
