Show simple item record

dc.contributor.authorCrans, D. C.en
dc.contributor.authorHolst, H.en
dc.contributor.authorKeramidas, Anastasios D.en
dc.contributor.authorRender, D.en
dc.creatorCrans, D. C.en
dc.creatorHolst, H.en
dc.creatorKeramidas, Anastasios D.en
dc.creatorRender, D.en
dc.date.accessioned2019-11-21T06:18:39Z
dc.date.available2019-11-21T06:18:39Z
dc.date.issued1995
dc.identifier.urihttp://gnosis.library.ucy.ac.cy/handle/7/55392
dc.description.abstractThe solution structure and rate of formation for a vanadium(V)-peptide complex, vanadium(V)-glycine-tyrosine (V-Gly-Tyr), is examined. Multinuclear NMR spectroscopic studies suggest the amide nitrogen is deprotonated and chelated to the vanadium as observed in peptide complexes of Ni(II) and Cu(II). The carboxylate and the amine groups in the dipeptide also appear to be chelated to the vanadium atom. The rate law for V-Gly-Tyr complex formation suggests that the complex is generated according to two major pathways, both involving H2VO4 − and deprotonated glycine-tyrosine dipeptide (Gly-Tyr−), one with and one without acid catalysis. The rate constant for the first pathway was 1.0 (±0.1) M−2 min‒1 (0.017 (±0.002) M‒2 s‒1), and the rate constant for the second pathway was 1.5 (±0.1) M‒1 min−1 (0.025 (±0.003) M−1 s‒1) The kinetics of complex formation were found to be significantly different from reported vanadate complexes such as vanadate dimer, vanadium(V)- alizarin, vanadium(V)-N-[tris(hydroxymethyl)methyl]glycine, vanadium(V)-EDTA, and vanadium(V)-ATPase. All of the previously studied complexes formed with H3O+ independent rate constants of about 104 M−1 s−1. The slow rates of formation of V-Gly-Tyr imply that equilibrium in such solutions is only slowly achieved. Time dependence curves reveal that the other complexes in the reaction between vanadate and Gly-Tyr form even more slowlyen
dc.description.abstracthowever, such complexes are likely to be oxidation products since these complexes were not observed when oxygen was excluded from the solutions. Only low levels of vanadium(IV) complexes were observed in the absence or the presence of oxygen, despite significant concentrations of oxidation products. These observations are consistent with the recycling of the vanadium(IV) to vanadium(V) under the consumption of oxygen. Increasing temperatures also increase the V-Gly-Tyr concentration, however, since the vanadate monomer (V1) concentration increases, little variation in the formation constant is observed. The reaction of vanadate with Gly-Ser was also found to be significantly slower than the formation of vanadate esters and required incubation for more than an hour before equilibrium was achieved. It appears that complex formation between vanadate and ligands containing the peptide functionalities occurs slowly, analogous to formation of peptide complexes of Ni(II) and Cu(II). © 1995, American Chemical Society. All rights reserved.en
dc.sourceInorganic chemistryen
dc.source.urihttps://www.scopus.com/inward/record.uri?eid=2-s2.0-0000382047&doi=10.1021%2fic00114a009&partnerID=40&md5=59f439138d97508012d58f6b60e04369
dc.titleA Slow Exchanging Vanadium(V) Peptide Complex: Vanadium(V)-Glycine-Tyrosineen
dc.typeinfo:eu-repo/semantics/article
dc.identifier.doi10.1021/ic00114a009
dc.description.volume34
dc.description.issue10
dc.description.startingpage2524
dc.description.endingpage2534
dc.author.faculty002 Σχολή Θετικών και Εφαρμοσμένων Επιστημών / Faculty of Pure and Applied Sciences
dc.author.departmentΤμήμα Χημείας / Department of Chemistry
dc.type.uhtypeArticleen
dc.description.notes<p>Cited By :63</p>en
dc.source.abbreviationInorg.Chem.en
dc.contributor.orcidKeramidas, Anastasios D. [0000-0002-0446-8220]
dc.gnosis.orcid0000-0002-0446-8220


Files in this item

FilesSizeFormatView

There are no files associated with this item.

This item appears in the following Collection(s)

Show simple item record