Bioinsecticidal activity of a novel Kunitz trypsin inhibitor from Catanduva (Piptadenia moniliformis) seeds.
Plant Physiol Biochem
; 70: 61-8, 2013 Sep.
Article
em En
| MEDLINE
| ID: mdl-23770595
The present study aims to provide new in vitro and in vivo biochemical information about a novel Kunitz trypsin inhibitor purified from Piptadenia moniliformis seeds. The purification process was performed using TCA precipitation, Trypsin-Sepharose and reversed-phase C18 HPLC chromatography. The inhibitor, named PmTKI, showed an apparent molecular mass of around 19 kDa, visualized by SDS-PAGE, which was confirmed by mass spectrometry MALDI-ToF demonstrating a monoisotopic mass of 19.296 Da. The inhibitor was in vitro active against trypsin, chymotrypsin and papain. Moreover, kinetic enzymatic studies were performed aiming to understand the inhibition mode of PmTKI, which competitively inhibits the target enzyme, presenting Ki values of 1.5 × 10(-8) and 3.0 × 10(-1) M against trypsin and chymotrypsin, respectively. Also, the inhibitory activity was assayed at different pH ranges, temperatures and reduction environments (DTT). The inhibitor was stable in all conditions maintaining an 80% residual activity. N-terminal sequence was obtained by Edman degradation and the primary sequence presented identity with members of Kunitz-type inhibitors from the same subfamily. Finally after biochemical characterization the inhibitory effect was evaluated in vitro on insect digestive enzymes from different orders, PmTKI demonstrated remarkable activity against enzymes from Anthonomus grandis (90%), Plodia interpuncptella (60%), and Ceratitis capitata (70%). Furthermore, in vivo bioinsecticidal assays of C. capitata larvae were also performed and the concentration of PmTKI (w/w) in an artificial diet required to LD50 and ED50 larvae were 0.37 and 0.3% respectively. In summary, data reported here shown the biotechnological potential of PmTKI for insect pest control.
Palavras-chave
Bioinsecticidal; DTT; ED50; HPLC; Insect pests; Ki; Kunitz trypsin inhibitor; LD50; MALDI-ToF; Piptadenia moniliformis; TCA; TFA; dithiothreitol; effective dose to inhibit 50% of an enzymatic pool; high-performance liquid chromatography; inhibition constant; lethal dose to kill 50% of an insect population; matrix assisted laser desorption ionization time of flight mass spectrometry; trichloroacetic acid; trifluoroacetic acid
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Plantas
/
Sementes
/
Tripsina
/
Inibidores da Tripsina
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Inseticidas
/
Insetos
/
Fabaceae
Limite:
Animals
Idioma:
En
Revista:
Plant Physiol Biochem
Assunto da revista:
BIOQUIMICA
/
BOTANICA
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
França