Purification, characterization, and complete amino acid sequence of a trypsin inhibitor from amaranth (Amaranthus hypochondriacus) seeds.

AUTOR(ES)

Valdes-Rodriguez, S

RESUMO

A protein proteinase inhibitor was purified from a seed extract of amaranth (Amaranthus hypochondriacus) by precipitation with (NH4)2SO4, gel-filtration chromatography, ion-exchange chromatography, and reverse-phase high-performance liquid chromatography. It is a 69-amino acid protein with a high content of valine, arginine, and glutamic acid, but lacking in methionine. The inhibitor has a relative molecular weight of 7400 and an isoelectric point of 7.5. It is a serine proteinase inhibitor that recognizes chymotrypsin, trypsin, and trypsin-like proteinase activities extracted from larvae of the insect Prostephanus truncatus. This inhibitor belongs to the potato-I inhibitor family, showing the closest homology (59.5%) with the Lycopersicum peruvianum trypsin inhibitor, and (51%) with the proteinase inhibitor 5 extracted from the seeds of Cucurbita maxima. The position of the lysine-aspartic acid residues present in the active site of the amaranth inhibitor are found in almost the same relative position as in the inhibitor from C. maxima.

Documentos Relacionados

• Extraction, purification and characterization of inhibitor of trypsin from Chenopodium quinoa seeds
• Purification, Characterization, and Sequence Analysis of a Potential Virulence Factor from Porphyromonas gingivalis, Peptidylarginine Deiminase
• Nucleotide sequence of rbcL from Amaranthus hypochondriacus chloroplasts.
• Purification and Characterization of Allene Oxide Cyclase from Dry Corn Seeds.
• Purification, Enzymatic Characterization, and Nucleotide Sequence of a High-Isoelectric-Point α-Glucosidase from Barley Malt1