Respiratory proteins

TRIR methods have also found utility in the elucidation of reaction mechanisms involved in biological systems, most notably photosynthetic and respiratory proteins. In addition, TRIR spectroscopy has also been used to enhance our understanding of the dynamics of protein folding processes. ... 

Hemerythrin is a respiratory protein isolated from sipun-culids (marine worms). All sipunculids examined have, in the coelomic fluid, erythrocytes loaded with the protein which in most species so far examined is octameric, but sometimes tri-meric (18, 19) and in one instance dimeric and tetrameric (20, 21). From the retractor muscle of Themiste zostericola, the protein has been characterized as a monomer (22). The monomer (23) and the subunits of the trimer (24) and octamer (25) are remarkably similar in tertiary structure, having a M.W. of about 13,500 daltons. Each subunit contains one binuclear iron site. There is no porphyrin ring and the irons are coordinated only to amino acids, some of which, as well as probably an oxy group, form the binding atoms (26). 

The interaction of Fe(II) with small molecules has received much attention. The Fe(II)/ oxygen system must be one of the most studied chemical interactions. Since the Fe-porphyrin complex forms the core of the naturally occurring iron respiratory proteins myoglobin and... 

L. B. Mendel and H. C. Bradley found in 1905 diat the snail syco-typus contains zinc in the fiver and in die oxygen-carrying protein of the blood, liemosycotypin. The diree respiratory proteins, hemoglobin of the vertebrates, hemocyanin of die octopus, and hemosycotypin of the... 

Oct. 8,1904 1904 1904-5 1905 Death of Winkler. Death of Demargay at Paris. Giesel and Godlewski independently discover actinium X. L. B. Mendel and H. C. Bradley discover zinc in the liver and respiratory protein of the snail Sycotypus. 

Parr, S. R., Barber, D., Greenwood, C., Phillips, B. W., and Melling, J. (1976). A purification ptocedure for the soluble cytochrome oxidase and some other respiratory proteins from Pseudomonas aeruginosa. Biochem. J. 157, 423-430. 

TABLE 19-6 Respiratory Proteins Encoded by Mitochondrial Genes in Humans... 

Active fish have a better developed capillary system in the red muscle to supply oxygen to the mitochondria, and a higher haematocrit (Blaxter et al., 1971). The red muscle tissue also contains more cytochromes (respiratory proteins), and exhibits more cytochrome oxidase activity, which is responsible for transferring electrons in die respiratory chain, more efficient respiration control (oxidative phosphorylation and P/O coefficient) and a greater Atkinson charge, which characterizes energy reserve accumulated in adenyl nucleotides ... 

Lypically wiLh one 02 binding site on each subunit. Molluscan Hcs, in contrast are constructed from much larger subunits each carrying seven or eight binding sites. Current concepts propose that most invertebrate respiratory proteins (with the exception of Hb) evolved as 02 carriers after the initial branchings of the major invertebrate phyla, almost certainly in pre-Cambrian times (van Holde, 1998). 

There is considerable overlap between the iron-rich areas of the brain and those regions where GABA neurones terminate. In these regions, approximately 30% of the iron is bound to ferritin, the remainder being associated with enzymes, respiratory proteins and transferrin. A large proportion... 

The vitamin B12 and related coenzymes (cobalamins, cobinamides, and corrinoids) have been studied in detail using H and shift and relaxation studies. (595-598) With the aid of lanthanide probes the eonformations of cobalamins in solution are shown to be very similar to those in the crystalline state. The appreciable temperature dependences of the electronic and H NMR spectra are attributed to a conformational change rather than to a 6-eoordinate-5-coordinate equilibrium as previously suggested. (599) The binding of 5 -ATP to the respiratory protein hemoeyanin has been studied by H and NMR. 

---