Adaptation of tobacco budworm Heliothis virescens to proteinase inhibitors may be mediated by the synthesis of new proteinases

被引:74
作者
Brito, LO
Lopes, AR
Parra, JRP
Terra, WR
Silva-Filho, MC
机构
[1] Univ Sao Paulo, Dept Genet, Escola Super Agr Luiz de Queiroz, BR-13400970 Piracicaba, SP, Brazil
[2] Univ Sao Paulo, Inst Quim, Dept Bioquim, BR-05513970 Sao Paulo, Brazil
[3] Univ Sao Paulo, Dept Entomol, Escola Super Agr Luiz de Queiroz, BR-13418900 Piracicaba, SP, Brazil
来源
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY | 2001年 / 128卷 / 02期
基金
巴西圣保罗研究基金会;
关键词
proteinase inhibitors; insect adaptation; insect resistance; Heliothis virescens; midgut proteinases; trypsin; chymotrypsin; trypsin oligomerization; Lepidoptera;
D O I
10.1016/S1096-4959(00)00325-0
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The tobacco budworm Heliothis virescens is adapted to feed on tobacco leaves that have proteinase protein inhibitors (PIs). To study this adaptation, the midgut proteinases of Heliothis virescens larvae reared on artificial PI-free diet and on tobacco leaves were compared using ion exchange chromatography, hydrophobic chromatography. gel filtration and polyacrylamide gel electrophoresis at different conditions. SDS polyacrylamide-gradient gel electrophoresis (SDS-PAGE) and kinetic studies shown that leaf-fed larvae have a chymotrypsin (M-r 26000) and four trypsins (T1-T4) with the following properties: TI, K-m 0.3 muM. M-r 70000; T2, K-m 0.4 muM, M-r 67000; T3, K-m 2.4 muM, M-r 29000; T4, K-m 15 muM M-r 17000, Diet-fed larvae have a chymotrypsin (M-r 26000) and a major trypsin (K-m 2.9 muM, M-r 29000). Native PAGE at different gel concentrations showed that in these conditions, only T1 and T2 occur in leaf-fed larvae, whereas gel filtration in the absence and presence of SDS revealed that T1 and T2 might arise by polymerization of T3 and T4, respectively. The data suggest that, in the presence of PI-containing food, H. virescens larvae express new trypsin molecules that form oligomers and are apparently less affected by PIs because of tighter binding to the substrate (lower K-m values) and a putative decreased affinity for PIs, (C) 2001 Elsevier Science Inc. All rights reserved.
引用
收藏
页码:365 / 375
页数:11
相关论文
共 39 条
[1]  
Alves LC, 1996, PEPTIDE RES, V9, P92
[2]   NATURAL PROTEIN PROTEINASE-INHIBITORS AND THEIR INTERACTION WITH PROTEINASES [J].
BODE, W ;
HUBER, R .
EUROPEAN JOURNAL OF BIOCHEMISTRY, 1992, 204 (02) :433-451
[3]   Differentially regulated inhibitor-sensitive and insensitive protease genes from the phytophagous insect pest, Helicoverpa armigara, are members of complex multigene families [J].
Bown, DP ;
Wilkinson, HS ;
Gatehouse, JA .
INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY, 1997, 27 (07) :625-638
[4]  
BRADFORD MM, 1976, ANAL BIOCHEM, V72, P248, DOI 10.1016/0003-2697(76)90527-3
[5]   ARE INSECTS RESISTANT TO PLANT PROTEINASE-INHIBITORS [J].
BROADWAY, RM .
JOURNAL OF INSECT PHYSIOLOGY, 1995, 41 (02) :107-116
[6]  
Broadway RM, 1996, ARCH INSECT BIOCHEM, V32, P39, DOI 10.1002/(SICI)1520-6327(1996)32:1&lt
[7]  
39::AID-ARCH3&gt
[8]  
3.0.CO
[9]  
2-S
[10]   Dietary regulation of serine proteinases that are resistant to serine proteinase inhibitors [J].
Broadway, RM .
JOURNAL OF INSECT PHYSIOLOGY, 1997, 43 (09) :855-874