PROPERTIES OF THE DIGESTIVE ENZYMES AND THE PERMEABILITY OF THE PERITROPHIC MEMBRANE OF SPODOPTERA-FRUGIPERDA (LEPIDOPTERA) LARVAE
PROPERTIES OF THE DIGESTIVE ENZYMES AND THE PERMEABILITY OF THE PERITROPHIC MEMBRANE OF SPODOPTERA-FRUGIPERDA (LEPIDOPTERA) LARVAE
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DOI：
10.1016/0300-9629(94)90362-x
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发表时间：
1994-04-01
影响因子：
2.3
通讯作者：
TERRA, WR
中科院分区：
文献类型：
--
作者：
FERREIRA, C;CAPELLA, AN;TERRA, WR
研究了几种可溶性和洗涤剂增溶的膜结合中肠水解酶的物理和动力学性质。采用等电聚焦和聚丙烯酰胺凝胶电泳法、密度梯度超速离心法和超糖柱凝胶过滤技术。在体内，水解酶的分子量被认为与离心法测定的分子量一致，离心法是所采用的程序中更温和的方法。根据这一标准，可溶性水解酶显示以下亚基数目：乙酰氨基葡萄糖苷酶[pHo5(最适pH)，Mr 123,000]，2；氨基肽酶(pho 7.4，Mr 107,000)，2；淀粉酶(pho 9.6，Km，淀粉0.38%，Mr 87,000)，1；羧肽酶A(pho 8.0，Mr 45,000)，2；纤维二糖酶(pho 7.0，Mr 124,000)，2；二肽酶(pho 8.0，Mr 95,000)，2；麦芽糖酶(pho 5.0，Mr 150,000)，2；胰酶(pho 7.9，Mr 51,000)，2.淀粉酶不被氯化物激活。通过营养周膜的酶(淀粉酶、羧基肽酶和胰酶)与分泌到管腔但不通过营养周膜的酶(乙酰氨基葡萄糖胺酶)的直径比较，果蝇幼虫营养周膜的孔径为7.5-8 nm。
The physical and kinetic properties of several soluble and detergent-solubilized membrane-bound midgut hydrolases of Spodoptera frugiperda (Lepidoptera) were investigated. The following techniques were employed: isoelectric focusing and electrophoresis in polyacrylamide gels, density-gradient ultracentrifugation and gel filtration in Superose columns. In vivo molecular weights of the hydrolases were considered to correspond with those determined by centrifugation, which is the more gentle of the procedures employed. Using this criterion, the soluble hydrolases display the following number of sub-units: acetylglucosaminidase [pHo5 (pH optimum), Mr 123,000], 2; aminopeptidase (pHo 7.4, Mr 107,000), 2; amylase (pHo 9.6, Km for starch 0.38%, Mr 87,000), 1; carboxypeptidase A (pHo 8.0, Mr 45,000), 2; cellobiase (pHo 7.0, Mr 124,000), 2; dipeptidase (pHo 8.0, Mr 95,000), 2; maltase (pHo 5.0, Mr 150,000), 2; trypsin (pHo 7.9, Mr 51,000), 2. Amylase is not activated by chloride. A comparison between the diameters of the enzymes which pass through the peritrophic membrane (amylase, carboxypeptidase and trypsin) with that which is secreted into the lumen but do not pass through the peritrophic membrane (acetylglucosaminase) suggests that the pores of S. frugiperda larval peritrophic membrane have diameters of 7.5-8 nm.