The biochemical adaptations

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  • Research in anoxic environments is a relatively new and rapidly growing branch of science that is of general interest to many students of diverse microbial communities. The term anoxia means absence of atmospheric oxygen, while the term hypoxia refers to O 2 depletion or to an extreme form of “low oxygen.” Both terms anoxia and hypoxia are used in various contexts. It is accepted that the initial microorganisms evolved anaerobically and thrived in an atmosphere without oxygen. The rise of atmospheric oxygen occurred ~2.

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  • Adaptation to extreme environments affects the stability and catalytic effi-ciency of enzymes, often endowing them with great industrial potential. We compared the environmental adaptation of the secreted endonuclease I from the cold-adapted marine fish pathogenVibrio salmonicida(VsEndA) and the human pathogen Vibrio cholerae (VcEndA).

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  • Chlamydomonas reinhardtii, a unicellular green alga, contains a hydrogenase enzyme, which is induced by anaerobic adaptation of the cells. Using the suppression subtractive hybridization (SSH) approach, the differential expression of genes under anaerobiosis was analyzed. A PCR fragment with similarity to the genes of bacterial Fe-hydrogenases was isolated and used to screen an anaerobic cDNA expression library of C. reinhardtii.

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  • Goldfish (Carassius auratus) may survive in aquatic environments with low oxygen partial pressures. We investigated the contribution of respiratory proteins to hypoxia tolerance inC. auratus. We determined the complete coding sequence of hemoglobinaandband myoglobin, as well as partial cDNAs from neuroglobin and cytoglobin.

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  • The effects of physiologically relevant hypoxia on the catalytic activity of cytochromecoxidase (CytOX), mito-chondrial gene expression, and both nuclear and mito-chondrial encoded CytOX mRNA levels were investigated in murine monocyte macrophages, mouse C2C12 skeletal myocytes and rat adrenal pheochromocytoma PC12 cells. Our results suggest a coordinated down regulation of mito-chondrial genome-coded CytOX I and II and nuclear genome-codedCytOX IV andVbmRNAs during hypoxia.

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  • The heat shock response was originally characterized as the induction of a set of major heat shock proteins encoded by heat shock genes. Because heat shock proteins act as molecular chaperones that facilitate protein fold-ing and suppress protein aggregation, this response plays a major role in maintaining protein homeostasis.

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  • The term ‘antimicrobial peptides’ refers to a large number of peptides first characterized on the basis of their antibiotic and antifungal activities. In addition to their role as endogenous antibiotics, antimicrobial peptides, also called host defense peptides, participate in multiple aspects of immunity (inflammation, wound repair, and regulation of the adaptive immune sys-tem) as well as in maintaining homeostasis.

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  • The dominant perciform suborder Notothenioidei is an excellent study group for assessing the evolution and functional importance of biochemical adaptations to temperature. The availability of notothenioid taxa in a wide range of latitudes (Antarctic and non-Antarctic) provides a tool to enable identification of physiological and biochemical characteristics gained and lost during evolutionary history.

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  • In living organisms, genes encoding proteins that contain flavins as a pros-thetic group constitute approximately 2–3% of the total. The fluorescence of flavin cofactors in these proteins is a property that is widely employed for biochemical characterisation. Here, we present a modified Thermofluor  approach called ThermoFAD (Thermofluor  -adapted flavin ad hoc detec-tion system), which simplifies identification of optimal purification and storage conditions as well as high-affinity ligands.

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  • Transmissible spongiform encephalopathies (TSEs), or prion diseases, are fatal neurodegenerative disorders caused by an infectious agent termed a prion, which can convert normal cellular prion protein (PrP C ) into a patho-logically misfolded isoform (PrP Sc ). Taking advantage of protein misfolding cyclic amplification (PMCA), a series of experiments was conducted to investigate the possible influences of pyridine nucleotides on the propaga-

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  • The soil ecosystem provides services such as carbon sequestration, nutrient cycling, water purification, provisioning of industrial and pharmaceutical goods, and a mitigating sink for chemical and biological agents. However, the soil is subject to various degradation processes. Its relation with the hydrosphere, biosphere, and atmosphere makes the interacting processes even more complex. Moreover, as the soilhuman interactions increase, threats, leading to a series of impacts on soil health, become more important....

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  • The biotic world is doubtlessly the best known example of what Nobelist Murray Gell-Mann has termed ‘‘complex adaptive systems’’—a name given to those systems possessing the innate capacity to learn and evolve by utilizing acquired information. Those familiar with living systems cannot but marvel at each cell’s ability to grow, to sense, to communicate, to cooperate, to move, to proliferate, to die and, even then, to yield opportunity to succeeding cells.

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  • Effective new treatments of heart disease are based on a refined understanding of cellular function and the heart's response to environmental stresses. Not surprisingly therefore, the field of experimental cardiology has experienced a phase of rapid exponential growth during the last decade. The acquisition of new knowledge has been so fast that textbooks of cardiology or textbooks of cardiovascular physiology are often hard-pressed to keep up with the most important conceptual advances.

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  • Define ecological biochemistry. • Explain biochemical adaptation and the roles of secondary compounds. • Describe detoxification and the primary metabolic pathways in plants and animals. • Explain the key processes and factors involved in biotransformation & biodegradation. • Explain the concepts of sequestration, bioaccumulation, and biomagnification. • Contrast different forms of ecological biochemical interaction.

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  • Peroxisomes are cell organelles that are present in almost all eukaryotic cells and involved in a large range of metabolic pathways. The organelles are highly dynamic in nature: their number and enzyme content is highly variable and continuously adapts to prevailing environmental conditions. This review summarizes recent relevant developments in research on pro-cesses that are involved in the regulation of peroxisome abundance and maintenance.

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  • In ruminants, some leaf-eating animals, and some insects, defensive lyso-zymes have been adapted to become digestive enzymes, in order to digest bacteria in the stomach. Digestive lysozyme has been reported to be resis-tant to protease and to have optimal activity at acidic pH. The structural basis of the adaptation providing persistence of lytic activity under severe gastric conditions remains unclear.

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  • When challenged by the dietary soybean cysteine protease inhibitor scN, the cowpea bruchid (Callosobruchus maculatus) adapts to the inhibitory effects by readjusting the transcriptome of its digestive system, including the specific activation of a cathepsin B-like cysteine protease CmCatB.

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  • Riftia pachyptila(Vestimentifera) is a giant tubeworm living around the volcanic deep-sea vents of the East Pacific Rise. This animal is devoid of a digestive tract and lives in an intimate symbiosis with a sulfur-oxidizing chemoauto-trophic bacterium. This bacterial endosymbiont is localized in the cells of a richly vascularized organ of the worm: the trophosome.

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  • The classical metabolic control theory [Kacser, H. & Burns, J.A. (1973)Symp.Soc.Exp.Biol. 27, 65–104; Heinrich, R. & Rapoport, T. (1974)Eur. J. Biochem.42, 89–95.] does not take into account experimental evidence for correlations between enzyme concentrations in the cell. We investigated the implications of two causes of linear correlations: competition between enzymes, which is a mere physical adaptation of the cell to the limitation of resources and space, and regulatory correlations, which result from the existence of regulatory networks....

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  • The digestive tract of lepidopteran insects is extremely alkaline. In the pres-ent work, molecular adaptation of amylolytic enzymes to this environment was investigated in the flour moth Ephestia kuehniella, an important stored-product pest. Three digestivea-amylases [Ephestia kuehniellaa-amy-lase isoenzymes 1–3 (EkAmy1–3)] with an alkaline pH optimum were puri-fied from larvae and biochemically characterized.

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