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Metal binding novel flaxseed peptides (linusorbs)
Author(s) -
Jadhav Pramodkumar D.,
Zuo Yang,
Shim Youn Young,
Shen Jianheng,
Reaney Martin J. T.,
Zhang Ning,
Wang Yong
Publication year - 2018
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/ijfs.13786
Subject(s) - metal , chemistry , metal ions in aqueous solution , methionine , peptide , nuclear chemistry , mass spectrometry , amino acid , inorganic chemistry , stereochemistry , chromatography , organic chemistry , biochemistry
Summary Linusorbs ( LO s; a.k.a. cyclolinopeptides) are naturally occurring orbitides derived from flaxseed. These compounds consist of 8–10 amino acid residues, which are linked via an N ‐ to C‐terminal peptide bond with molecular masses of approximately 1 kD a. The LO circular structure makes them candidates for metal binding studies. Flaxseed extracts are known to suppress Pb and Cd toxicity. Hence, four metal salts surveyed include Zn( CH 3 COO ) 2 , Zn SO 4 , Pb( CH 3 COO ) 2 and Cd( NO 3 ) 2 with pure LO s 1–5 . Proton NMR spectra indicated interaction of LO s with metal salts in solution and were used to determine impacts of methionine oxidation on interactions with metal ions. The methyl group of methionine S,S ‐ dioxide of related LO s did not show the same shift in the presence of Zn( CH 3 COO ) 2 and Pb( CH 3 COO ) 2 observed in their methionine S ‐ oxide analogues. Metal complexes were observed forming at 10 −2 m to 10 −4 m but not at lower concentrations (10 −5 m to 10 −8 m ). Mass spectrometry data confirmed that metal binding strength varied by metal in the order Zn( CH 3 COO ) 2