Myoglobin functional role

Metals at the active sites of metalloproteins display special properties and are generally impressively efficient in their functional roles. The metal or metals are said to be poised for catalytic action or in an entatic state, an expression first used by Vallee and Williams in their seminal paper of 1968 (2). The fine tuning or control of the peptide in many cases results in previously unobserved aspects of the coordination chemistry of the metal in question. There are many examples, almost as many as there are metalloproteins, from (in the case of Fe) the five-coordinate high-spin Fe(II) in myoglobin and hemoglobin... 

O Brien, P. J. et al. 1992. Rapid, simple and sensitive microassay for skeletal and cardiac muscle myoglobin and hemoglobin Use in various animals indicates functional role of myohemoproteins. Molecular and Cellular Biochemistry 112 45-52. 

H. Frauenfelder, B.H. McMahon, R.H. Austin, K. Chu, and J.T. Groves, The role of structure, energy landscape, dynamics, and allostery in the enzymatic function of myoglobin. Proc. Natl. Acad. Sci. 98, 2370(2001). 

Molecular dynamics (MD) simulations [29-31], coupled with experimental observations, have played an important role in the understanding of protein hydration. They predicted that the dynamics of ordered water molecules in the surface layer is ultrafast, typically on the picosecond time scales. Most calculated residence times are shorter than experimental measurements reported before, in a range of sub-picosecond to 100 ps. Water molecules at the surface are very mobile and are in constant exchange with bulk water. For example, the trajectory study of myoglobin hydration revealed that among 294 hydration sites, the residence times at 284 sites (96.6% of surface water molecules) are less than lOOps [32]. Furthermore, the population time correlation functions... 

Mb is one of the highly characterized proteins and is considered to be a good model molecule for the analysis of the dynamics of the structural changes in general proteins. In attempts to elucidate the role of the protein dynamics toward their function, the recombination of photodissociated CO of carbonmonoxy myoglobin (COMb) has been extensively investigated over times that range from femtoseconds to seconds at various temperatures. 

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