English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The N-terminal native sequence tripeptide of alpha-fetoprotein, L-threonyl-L-leucyl-L-histidine N-methylamide, was synthesized and its interaction with Cu(II) ions was investigated by potentiometric titration at 25 degrees C in 0.15 M-NaCl and by visible-absorption, e.p.r. and n.m.r. spectroscopy. Analyses of the results in the pH range 4-10 indicated the presence of multiple complex species in solution: MHL, MH-2L, MHL2, ML2 and MH-1L2, where M, H and L represent metal ion, proton and ligand anion respectively. Only the species MH-2L and MH-1L2 are present in significant amounts at physiological pH. The results of the visible-absorption spectroscopy are consistent with the findings of species distribution that MH-2L is the major complex species detected above physiological pH that has the spectral characteristics of lambda max. = 523 nm and epsilon max. = 98 M-1.cm-1. The nine superhyperfine lines in e.p.r. spectra of the major species MH-2L strongly support the co-ordination of four nitrogen atoms by Cu(II). Both 1H- and 13C-n.m.r. studies suggest that the species MH-2L is a square-planar complex. The results from the equilibrium-dialysis experiments showed that this peptide is able to compete with albumin for Cu(II) ions. At equimolar concentrations of albumin and the peptide, about 52% of the Cu(II) was bound to the peptide. The possibility that alpha-fetoprotein plays an important role as the Cu(II)-transport protein in fetal life is discussed.

Synthesis and copper(II)-binding properties of the N-terminal peptide of human α-fetoprotein