Proteins respiration

Experiments on the respiration of detached leaves not only illustrate the control of respiration rate by availability of respiratory substrates but illustrate very clearly that not only carbohydrates but also proteins may be respired. This protein respiration involves protein hydrolysis to yield amino acids and amides, deamination of these amino acids and subsequent decarboxylation (leading to carbon dioxide release) and oxidation of the resulting organic acids. 

Protein respiration almost certainly involves first a hydrolytic breakdown by proteinases and peptidases to give free amino acids. Of the amino acids of plant cells, only glutamic acid is known to be actively oxidised by an enzyme universally distributed, the glutamic acid dehydrogenase ... 

Potassium [7440-09-7] K, is the third, element ia the aLkaU metal series. The name designation for the element is derived from potash, a potassium mineral the symbol from the German name kalium, which comes from the Arabic qili, a plant. The ashes of these plants al qili) were the historical source of potash for preparing fertilisers (qv) or gun powder. Potassium ions, essential to plants and animals, play a key role in carbohydrate metaboHsm in plants. In animals, potassium ions promote glycolysis, Hpolysis, tissue respiration, and the synthesis of proteins (qv) and acetylcholine. Potassium ions are also beheved to function in regulating blood pressure. 

Potassium is required for enzyme activity in a few special cases, the most widely studied example of which is the enzyme pymvate kinase. In plants it is required for protein and starch synthesis. Potassium is also involved in water and nutrient transport within and into the plant, and has a role in photosynthesis. Although sodium and potassium are similar in their inorganic chemical behavior, these ions are different in their physiological activities. In fact, their functions are often mutually antagonistic. For example, increases both the respiration rate in muscle tissue and the rate of protein synthesis, whereas inhibits both processes (42). 

FIGURE 5.13 Two basic types of biological transport are (a) transport within or between different cells or tissues and (b) transport into or out of cells. Proteins function in both of these phenomena. For example, the protein hemoglobin transports oxygen from the lungs to actively respiring tissues. Transport proteins of the other type are localized in cellular membranes, where they function in the uptake of specific nutrients, such as glucose (shown here) and amino acids, or the export of metabolites and waste products. 

On the other hand, the scrambled model of carbon sourcing does not seem to be applicable when we consider the metabolic fate of fatty acids. We find that there are partial barriers to the movement of FA-derived carbon atoms into the synthesis of proteins. This partial restriction leads us to expect a trophic level effect in the fractionation between collagen and bone apatite or respired CO2 of which apatitic carbonate is a sample. The magnitude of the fractionation depends on two separate fractionation factors which cannot be disentangled by analyses of bone samples alone. 

In contrast to common usage, the distinction between photosynthetic and respiratory Rieske proteins does not seem to make sense. The mitochondrial Rieske protein is closely related to that of photosynthetic purple bacteria, which represent the endosymbiotic ancestors of mitochondria (for a review, see also (99)). Moreover, during its evolution Rieske s protein appears to have existed prior to photosynthesis (100, 101), and the photosynthetic chain was probably built around a preexisting cytochrome be complex (99). The evolution of Rieske proteins from photosynthetic electron transport chains is therefore intricately intertwined with that of respiration, and a discussion of the photosynthetic representatives necessarily has to include excursions into nonphotosynthetic systems. 

Sergejeva S, Ivanov S, Lotvall J, Linden A Interleukin-17 as a recruitment and survival factor for airway macrophages in allergic airway inflammation. Am J Respir Cell Mol Biol 2005 33 248-253. 96 Bush KA, Farmer KM, Walker JS, Kirkham BW Reduction of joint inflammation and bone erosion in rat adjuvant arthritis by treatment with interleukin-17 receptor IgGl Fc fusion protein. Arthritis Rheum 2002 46 802-805. 

The many redox reactions that take place within a cell make use of metalloproteins with a wide range of electron transfer potentials. To name just a few of their functions, these proteins play key roles in respiration, photosynthesis, and nitrogen fixation. Some of them simply shuttle electrons to or from enzymes that require electron transfer as part of their catalytic activity. In many other cases, a complex enzyme may incorporate its own electron transfer centers. There are three general categories of transition metal redox centers cytochromes, blue copper proteins, and iron-sulfur proteins. 

Iron-sulfur (Fe-S) proteins function as electron-transfer proteins in many living cells. They are involved in photosynthesis, cell respiration, as well as in nitrogen fixation. Most Fe-S proteins have single-iron (rubredoxins), or two-, three-, or four-iron (ferredoxins), or even seven/eight-iron (nitrogenases) centers. 

In this chapter, a novel interpretation of the membrane transport process elucidated based on a voltammetric concept and method is presented, and the important role of charge transfer reactions at aqueous-membrane interfaces in the membrane transport is emphasized [10,17,18]. Then, three respiration mimetic charge (ion or electron) transfer reactions observed by the present authors at the interface between an aqueous solution and an organic solution in the absence of any enzymes or proteins are introduced, and selective ion transfer reactions coupled with the electron transfer reactions are discussed [19-23]. The reaction processes of the charge transfer reactions and the energetic relations... 

Cui CH, Adachi T, Oyamada H, et al. The role of mitogen-activated protein kinases in eotaxin-induced cytokine production from bronchial epithelial cells. Am J Respir Cell Mol Biol 2002 27(3) 329-335. 

Choi ES, Jakubzick C, Carpenter KJ, et al. Enhanced monocyte chemoattractant protein-3/CC chemokine ligand-7 in usual interstitial pneumonia. Am J Respir Crit Care Med 2004 170(5) 508-515. 

P14. Pohl, W., Kindas-Mugge, J., Kohn, H., Fitzal, S Micksche, M., and Kummer, F., Elevated heat shock protein 72 expression by human alveolar macrophages during the adult respiratory distress syndrome. Am. Rev. Respir. Dis. 147, A70(Abst) (1993). 

V6. Villar, J., Edelson, J. D., Post, M., Mullen, J. B. M., and Slutsky, A. S., Induction of heat stress proteins is associated with decreased mortality in an animal model of acute lung injury. Am. Rev. Respir. Dis. 147, 177-181 (1993). 

Nucleic acids are not the only biomolecules susceptible to damage by carotenoid degradation products. Degradation products of (3-carotene have been shown to induce damage to mitochondrial proteins and lipids (Siems et al., 2002), to inhibit mitochondrial respiration in isolated rat liver mitochondria, and to induce uncoupling of oxidative phosphorylation (Siems et al., 2005). Moreover, it has been demonstrated that the degradation products of (3-carotene, which include various aldehydes, are more potent inhibitors of Na-K ATPase than 4-hydroxynonenal, an aldehydic product of lipid peroxidaton (Siems et al., 2000). 

---