Use este identificador para citar ou linkar para este item: https://locus.ufv.br//handle/123456789/19887
Tipo: Artigo
Título: Partial purification and characterization of trypsin-like proteinases from insecticide-resistant and -susceptible strains of the maize weevil, Sitophilus zeamais
Autor(es): Silva, L.B.
Reis, A.P.
Pereira, E.J.G.
Oliveira, M.G.A.
Guedes, R.N.C.
Abstract: Serine proteinases from three strains of Sitophilus zeamais (Coleoptera: Curculionidae), one susceptible and two resistant to insecticides — one exhibiting fitness cost (resistant cost strain) and the other lacking it (resistant no-cost strain), were partially purified using an aprotinin–agarose affinity column providing purification factors ranging from 36.5 to 51.2%, with yields between 10 and 15% and activity between 529 and 875 µM/min/mg protein with the substrate N-α-benzoyl-l-Arg-p-nitroanilide (L-BApNA). SDS-PAGE of the purified fraction revealed a 56,000 Da molecular mass band in all strains and a 70,000 Da band more visible in the resistant no-cost strain. The purified proteinases from all strains were inhibited by phenylmethyl sulphonyl fluoride (PMSF), N-α-tosyl-l-lysine chloromethyl ketone (TLCK), aprotinin, benzamidine and soybean trypsin inhibitor (SBTI) characterizing them as trypsin-like serine proteinases. Trypsin-like proteinases from the resistant strains exhibited higher affinity for L-BApNA. The resistant no-cost strain exhibited Vmax-values 1.5- and 1.7-fold higher than the susceptible and resistance cost strains, respectively. A similar trend was also observed when using N-α-p-tosyl-L-Arg methyl ester (L-TAME) as substrate. These results provide support to the hypothesis that the enhanced serine proteinase activity may be playing a role in mitigating physiological costs associated with the maintenance of insecticide resistance mechanisms in some maize weevil strains.
Palavras-chave: Coleoptera
Cost mitigation
Enzyme kinetics
Fitness costs
Serine proteinases
Editor: Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology
Tipo de Acesso: Elsevier Inc.
URI: https://doi.org/10.1016/j.cbpb.2009.09.011
http://www.locus.ufv.br/handle/123456789/19887
Data do documento: 14-Out-2009
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