Data/hora: 02/06/2024 15:30:54

Provedor de dados: | 61
País: | Brazil
Título: | Purification and structural stability of a trypsin inhibitor from Amazon Inga cylindrica [Vell.] Mart. seeds
Autores: | Calderon,Leonardo A; Almeida Filho,Humberto A; Teles,Rozeni C. L; Medrano,Francisco J; Bloch Jr,Carlos; Santoro,Marcelo M; Freitas,Sonia M.
Data: | 2010-01-01
Ano: | 2010
Palavras-chave: | Inga cylindrica [Vell.] Mart; Leguminosae; Mimosoideae; Protease inhibitor; Protein stability; Trypsin inhibitor.
Resumo: | Inga cylindrica Trypsin Inhibitor (ICTI) was purified as a single polypeptide chain by one step anion-exchange chromatography from a crude extract of Inga cylindrica (Vell.) Mart. seeds. ICTI is a 19.5 kDa protein presenting a remarkable inhibitory activity against bovine trypsin (EC 3.4.21.4) (Ki = 4.3 nM). Circular dichroism analysis revealed that this inhibitor is a β type protein (40.4% of β-strand; 24.6% of β-turn and 6.7% of α-helix) in accordance with properties displayed in Kunitz type inhibitors. ICTI is a thermal stable protein within a wide range of pH (1.6 to 10.0) exhibiting highest stability at pH 7.0 as indicated by Tm of 70.0 ºC and ΔG25 of 48.5 ± 0.7 kJ.mol-1. The values of ΔG25 at pH 1.6 (22.5 ± 1.2 kJ.mol-1) and pH 10.0 (31.5 ± 1.0 kJ.mol-1) indicate a reduced structural stability of the protein under these conditions. This is likely to result from pKa differences of the acid and basic side chains reflecting the changes in the non-covalent interactions in the folded state.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202010000200001
Editor: | Brazilian Journal of Plant Physiology
Relação: | 10.1590/S1677-04202010000200001
Formato: | text/html
Fonte: | Brazilian Journal of Plant Physiology  v.22 n.2 2010
Fonte: | info:eu-repo/semantics/openAccess