Plays a major role in regulating hemoglobin oxygen affinity by controlling the levels of its allosteric effector 2,3-bisphosphoglycerate (2,3-BPG). Also exhibits mutase (EC 5.4.2.1) and phosphatase (EC 3.1.3.13) activities.
The chemical reactions and pathways involving carbohydrates, any of a group of organic compounds based of the general formula Cx(H2O)y. Includes the formation of carbohydrate derivatives by the addition of a carbohydrate residue to another molecule.
J. Biol. Chem. 264, 7837-7843 (1989)[PubMed:2542247]
Bisphosphoglycerate mutase (EC 5.4.2.4.) is a trifunctional enzyme which displays synthase, mutase, and phosphatase activities. The purification, characterization, and structural study of an abnormal form of the enzyme, isolated from a patient which we reported earlier (Rosa, R., Prehu, M. O., Beuzard, Y., and Rosa, J. (1978) J. Clin. Invest. 62, 907-915), is described. The abnormal enzyme, present at 50% of the level of the normal enzyme as estimated by immunological methods, showed elevated electrophoretic mobility and hybridized with erythrocyte phosphoglycerate mutase (EC 5.4.2.1.) in the same manner as the normal control. The mutant enzyme was unstable at 55 degrees C and could be protected against thermal instability by 0.5 mM glycerate 2,3-bisphoshate but not by either glycerate 3-phosphate or glycolate 2-phosphate. Two of the three functions of the mutant enzyme were distinct from those of the normal protein. The specific activity of the synthase was 0.57% of normal and that of the mutase 4.1%. By contrast, the specific phosphatase activity was not affected by the mutation. However, the phosphatase activity of the mutated protein was markedly less stimulated by glycolate-2-phosphate than that of the control. High performance liquid chromatography analysis of tryptic peptides derived from the mutant enzyme showed an abnormal profile with the absence of two peaks normally containing the T12 and T13 peptides and without the appearance of a supplementary peak. Amino acid sequence and mass spectrometric analysis demonstrated the substitution of Arg----Cys residue in position 89 producing an uncleaved T12-T13 present in the same peak as the T6. Considered together, our data suggest that Arg-89 is located at or near the active site of bisphosphoglycerate mutase and that this residue is probably involved in the binding of monophosphoglycerates.
The chemical reactions and pathways resulting in the breakdown of a monosaccharide (generally glucose) into pyruvate, with the concomitant production of a small amount of ATP. Glycolysis begins with phosphorylation of a monosaccharide (generally glucose) on the sixth carbon by a hexokinase, and ends with the production of pyruvate. Pyruvate may be converted to ethanol, lactate, or other small molecules, or fed into the TCA cycle.
The process of gaseous exchange between an organism and its environment. In plants, microorganisms, and many small animals, air or water makes direct contact with the organism's cells or tissue fluids, and the processes of diffusion supply the organism with dioxygen (O2) and remove carbon dioxide (CO2). In larger animals the efficiency of gaseous exchange is improved by specialized respiratory organs, such as lungs and gills, which are ventilated by breathing mechanisms.
J. Biol. Chem. 264, 7837-7843 (1989)[PubMed:2542247]
Bisphosphoglycerate mutase (EC 5.4.2.4.) is a trifunctional enzyme which displays synthase, mutase, and phosphatase activities. The purification, characterization, and structural study of an abnormal form of the enzyme, isolated from a patient which we reported earlier (Rosa, R., Prehu, M. O., Beuzard, Y., and Rosa, J. (1978) J. Clin. Invest. 62, 907-915), is described. The abnormal enzyme, present at 50% of the level of the normal enzyme as estimated by immunological methods, showed elevated electrophoretic mobility and hybridized with erythrocyte phosphoglycerate mutase (EC 5.4.2.1.) in the same manner as the normal control. The mutant enzyme was unstable at 55 degrees C and could be protected against thermal instability by 0.5 mM glycerate 2,3-bisphoshate but not by either glycerate 3-phosphate or glycolate 2-phosphate. Two of the three functions of the mutant enzyme were distinct from those of the normal protein. The specific activity of the synthase was 0.57% of normal and that of the mutase 4.1%. By contrast, the specific phosphatase activity was not affected by the mutation. However, the phosphatase activity of the mutated protein was markedly less stimulated by glycolate-2-phosphate than that of the control. High performance liquid chromatography analysis of tryptic peptides derived from the mutant enzyme showed an abnormal profile with the absence of two peaks normally containing the T12 and T13 peptides and without the appearance of a supplementary peak. Amino acid sequence and mass spectrometric analysis demonstrated the substitution of Arg----Cys residue in position 89 producing an uncleaved T12-T13 present in the same peak as the T6. Considered together, our data suggest that Arg-89 is located at or near the active site of bisphosphoglycerate mutase and that this residue is probably involved in the binding of monophosphoglycerates.
Biochem. J. 342 Pt 3, 581-596 (1999)[PubMed:10477269]
Over the last 25 years, several mathematical models of erythrocyte metabolism have been developed. Although these models have identified the key features in the regulation and control of erythrocyte metabolism, many important aspects remain unexplained. In particular, none of these models have satisfactorily accounted for 2,3-bisphosphoglycerate (2,3-BPG) metabolism. 2,3-BPG is an important modulator of haemoglobin oxygen affinity, and hence an understanding of the regulation of 2,3-BPG concentration is important for understanding blood oxygen transport. A detailed, comprehensive, and hence realistic mathematical model of erythrocyte metabolism is presented that can explain the regulation and control of 2,3-BPG concentration and turnover. The model is restricted to the core metabolic pathways, namely glycolysis, the 2,3-BPG shunt and the pentose phosphate pathway (PPP), and includes membrane transport of metabolites, the binding of metabolites to haemoglobin and Mg(2+), as well as pH effects on key enzymic reactions and binding processes. The model is necessarily complex, since it is intended to describe the regulation and control of 2,3-BPG metabolism under a wide variety of physiological and experimental conditions. In addition, since H(+) and blood oxygen tension are important external effectors of 2,3-BPG concentration, it was important that the model take into account the large array of kinetic and binding phenomena that result from changes in these effectors. Through an iterative loop of experimental and simulation analysis many values of enzyme-kinetic parameters of the model were refined to yield close conformity between model simulations and 'real' experimental data. This iterative process enabled a single set of parameters to be found which described well the metabolic behaviour of the erythrocyte under a wide variety of conditions.
Protein involved in the anaerobic enzymatic conversion of glucose to lactate or pyruvate, resulting in energy stored in the form of adenosine triphosphate (ATP), as occurs in skeletal muscle and in embryonic tissue.
Enzyme which catalyzes hydrolysis reaction, i.e. the addition of the hydrogen and hydroxyl ions of water to a molecule with its consequent splitting into two or more simpler molecules.
Enzyme that catalyzes the 1,1-, 1,2- or 1,3-hydrogen shift. The 1,1- hydrogen shift is an inversion at an asymmetric carbon center (racemases, epimerases). The 1,2-hydrogen shift involved a hydrogen transfer between two adjacent carbon atoms, one undergoing oxidation, the other reduction (aldose-ketose isomerases). The 1,3-hydrogen shifts are allylic or azaallylic (when nitrogen is one of the three atoms) isomerizations.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.