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Metalloproteins and Metallopeptides -
Natural Metallofoldamers
Vasiliki Lykourinou and Li-June Ming
Department of Chemistry, University of South Florida, USA
1.1 Introduction
By a combination of amino acids with various properties, it is possible to obtain the natu-
ral polymers, peptides and proteins, capable of catalyzing key transformations, sustaining
energy flow, and maintaining life in a narrow range of allowable conditions and starting
materials. The folding, flexibility, and structural changes of peptides and proteins are inte-
gral to their functions within living systems. Several factors affect their folding and con-
formation, including primary sequence, subunit composition, nature and type of subunit
interactions, presence of cofactors, and compartment and sequence during folding in a
well controlled environment. Emphasis must also be placed on the conformational flexi-
bility of peptides and proteins necessary in the context of their folding and function. In the
case of enzymes, such conformational flexibility renders the induced fit process possible
during enzymatic catalysis, as found in the large domain movements in hexokinase, HIV
protease, and many others upon substrate or inhibitor binding.
Protein conformation, structure, and function are often determined or modulated by
metal ions. Therefore, it is instructive to discuss the effect of metal ions or cofactors on
the conformational changes of proteins prior to and during their actions. Furthermore, by
comparing the folding of metallopeptides and metalloproteins to those whose conforma-
tional changes take place in the absence of metal ions can provide further structural and
functional information on the metal ions in the former molecules. Such discussion is
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