Glycosylation, amino acid analysis and kinetic properties of a major Kunitz-type trypsin inhibitor from Acacia victoriae Bentham seeds

Kah Ee, J. Zhao, Ata-Ur Rehman, Samson Agboola

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

An Acacia victoriae trypsin inhibitor (AvTI) was purified from the seeds of prickly wattle (A. victoriae Bentham) by salt precipitation, ion-exchange and gel filtration chromatography, and its degree of glycosylation, amino acid composition, and kinetic properties were determined. Gel electrophoresis revealed at least four glycoprotein bands in the crude extract, salt-precipitated and ion-exchange protein fractions, while the purified AvTI showed only one band and a degree of glycosylation of 2.06%. Glutamate (13.3%), aspartate (10.3%), leucine (7.62%) and lysine (7.01%) were the major amino acids in AvTI while the contents of sulphur-containing amino acids, cysteine (1.38%) and methionine (0.75%), as well as of tryptophan (1.17%) were low. Its dissociation constant (Ki) for the inhibition of bovine trypsin was found to be 1.06 × 10'8 M, indicating a high affinity between AvTI and this enzyme, and its role as a competitive inhibitor was confirmed by a double reciprocal plot. These results complement our earlier studies which indicated the presence of three isoforms of this Kunitz-type trypsin inhibitor in prickly wattle seed.
Original languageEnglish
Pages (from-to)1224-1227
Number of pages4
JournalFood Chemistry
Volume129
Issue number3
DOIs
Publication statusPublished - May 2011

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Kunitz-type proteinase inhibitor
Glycosylation
Acacia
Trypsin Inhibitors
glycosylation
Seed
Seeds
trypsin inhibitors
kinetics
Amino Acids
amino acids
Kinetics
seeds
Ion Exchange
ion exchange
Ion exchange
Salts
Gels
Sulfur Amino Acids
salts

Cite this

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title = "Glycosylation, amino acid analysis and kinetic properties of a major Kunitz-type trypsin inhibitor from Acacia victoriae Bentham seeds",
abstract = "An Acacia victoriae trypsin inhibitor (AvTI) was purified from the seeds of prickly wattle (A. victoriae Bentham) by salt precipitation, ion-exchange and gel filtration chromatography, and its degree of glycosylation, amino acid composition, and kinetic properties were determined. Gel electrophoresis revealed at least four glycoprotein bands in the crude extract, salt-precipitated and ion-exchange protein fractions, while the purified AvTI showed only one band and a degree of glycosylation of 2.06{\%}. Glutamate (13.3{\%}), aspartate (10.3{\%}), leucine (7.62{\%}) and lysine (7.01{\%}) were the major amino acids in AvTI while the contents of sulphur-containing amino acids, cysteine (1.38{\%}) and methionine (0.75{\%}), as well as of tryptophan (1.17{\%}) were low. Its dissociation constant (Ki) for the inhibition of bovine trypsin was found to be 1.06 {\~A}— 10'8 M, indicating a high affinity between AvTI and this enzyme, and its role as a competitive inhibitor was confirmed by a double reciprocal plot. These results complement our earlier studies which indicated the presence of three isoforms of this Kunitz-type trypsin inhibitor in prickly wattle seed.",
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author = "Kah Ee and J. Zhao and Ata-Ur Rehman and Samson Agboola",
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Glycosylation, amino acid analysis and kinetic properties of a major Kunitz-type trypsin inhibitor from Acacia victoriae Bentham seeds. / Ee, Kah; Zhao, J.; Rehman, Ata-Ur; Agboola, Samson.

In: Food Chemistry, Vol. 129, No. 3, 05.2011, p. 1224-1227.

Research output: Contribution to journalArticle

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AU - Ee, Kah

AU - Zhao, J.

AU - Rehman, Ata-Ur

AU - Agboola, Samson

N1 - Imported on 12 Apr 2017 - DigiTool details were: month (773h) = May, 2011; Journal title (773t) = Food Chemistry. ISSNs: 0308-8146;

PY - 2011/5

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N2 - An Acacia victoriae trypsin inhibitor (AvTI) was purified from the seeds of prickly wattle (A. victoriae Bentham) by salt precipitation, ion-exchange and gel filtration chromatography, and its degree of glycosylation, amino acid composition, and kinetic properties were determined. Gel electrophoresis revealed at least four glycoprotein bands in the crude extract, salt-precipitated and ion-exchange protein fractions, while the purified AvTI showed only one band and a degree of glycosylation of 2.06%. Glutamate (13.3%), aspartate (10.3%), leucine (7.62%) and lysine (7.01%) were the major amino acids in AvTI while the contents of sulphur-containing amino acids, cysteine (1.38%) and methionine (0.75%), as well as of tryptophan (1.17%) were low. Its dissociation constant (Ki) for the inhibition of bovine trypsin was found to be 1.06 × 10'8 M, indicating a high affinity between AvTI and this enzyme, and its role as a competitive inhibitor was confirmed by a double reciprocal plot. These results complement our earlier studies which indicated the presence of three isoforms of this Kunitz-type trypsin inhibitor in prickly wattle seed.

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KW - Kinetics

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