Disease relevance of BPGM

• Erythrocyte bisphosphoglycerate mutase (BPGM) deficiency is a rare disease associated with a decrease in 2,3-diphosphoglycerate concentration [1].
• We produced a recombinant human BPGM (rBPGM) by gene manipulation using E. coli and then obtained the polyclonal antibody by immunizing rabbits with purified rBPGM [2].
• Erythrocytosis due to bisphosphoglycerate mutase deficiency with concurrent glucose-6-phosphate dehydrogenase (G-6-PD) deficiency [3].

High impact information on BPGM

• The human erythrocyte 2,3-bisphosphoglycerate mutase (BPGM) is a multifunctional enzyme which controls the metabolism of 2,3-diphosphoglycerate, the main allosteric effector of haemoglobin [4].
• For this purpose, we have investigated the role of Gly-13, which is located in the active site sequence Arg9-His10-Gly11-Glu12-Gly13 in human BPGM [5].
• This sequence is similar to the Arg-His-Gly-Xaa-Arg* sequence of the distantly related acid phosphatases, which catalyze as BPGM similar phosphoryl transfers but to a greater extent [5].
• Since the erythrocyte glycerate 2,3-bisphosphate (2,3-DPG) has been shown to facilitate this polymerization, one therapeutic approach would be to decrease the intraerythrocytic level of 2,3-DPG by increasing the phosphatase activity of the bisphosphoglycerate mutase (BPGM; 3-phospho-D-glycerate 1,2-phosphomutase, EC 5.4.2.4) [5].
• A recombinant bisphosphoglycerate mutase variant with acid phosphatase homology degrades 2,3-diphosphoglycerate [5].

Biological context of BPGM

• In situ hybridization experiments localized the human BPGM gene to chromosome 7 and, more precisely, to region 7q34----7q22 [6].
• The seven amino acid residues, which have been shown to be essential for the three catalytic functions of the human BPGM, interact with the amino acids in the protein core, near the active site [7].
• Subunit interfaces have also been constructed for BPGM by analogy with MPGM and suggest that, in addition to the known dimerization of BPGM, tetramerization may occur under certain conditions [7].
• The revised amino acid sequence of the human BPGM is presented [8].
• Therefore, the total BPGM deficiency results from a genetic compound with one allele coding for an inactive enzyme (mutation BPGM Créteil I) and the other bearing a frameshift mutation (mutation BPGM Créteil II) [1].

Anatomical context of BPGM

• The BPGM synthesis represents 0.1% of the total neosynthesized non heme proteins in human reticulocyte and ten times less (0.01%) in human fetal liver [9].
• Northern blot analysis indicates that the 2,3-bisphosphoglycerate mutase mRNA is detected mainly in erythroid tissues and cell lines, although it is also present in low amounts in a nonerythroid tissue [10].
• Synthesis of 2,3-bisphosphoglycerate synthase in erythroid cells [11].

Associations of BPGM with chemical compounds

• Among several differences in the active site region the most significant appears to be the replacement of Ser11 in MPGM by Gly in BPGM [7].
• In summary, monophosphoglycerates and 2-phosphoglycolate have partially distinct binding sites in human BPGM [12].
• mRNAs prepared from different human tissues were translated in a cell-free reticulocyte lysate system and, when present, the neosynthesized bisphosphoglyceromutase ( BPGM ) was specifically isolated by immunoprecipitation and analyzed by polyacrylamide gel electrophoresis [9].
• At relatively low concentrations of 3-phosphoglyceroyl phosphate, the observed rate of 2,3-bisphosphoglycerate synthesis agreed with a rate calculated from a formula incorporating kinetic parameters of purified 2,3-bisphosphoglycerate synthase (Rose, Z.B. (1973) Arch. Biochem. Biophys. 158, 903-910) [13].
• These results show that the carboxyl-terminal amino acid residues are either directly or indirectly implicated in the three catalytic functions of the human bisphosphoglycerate mutase, and that the two terminal lysine residues are not essential for the major part of the enzymatic mechanism of the enzyme [14].

Other interactions of BPGM

• 2,3-Bisphosphoglycerate mutase (BPGM) [EC 5.4.2.4] is a multifunctional enzyme that catalyzes both the synthesis and the degradation of 2,3-diphosphoglycerate (2,3-DPG) and contains three types of activities in that it functions as a 2,3-DPG synthetase, a phosphoglycerate mutase and a 2,3-DPG phosphatase [15].
• No variations were observed for phosphoglycerate kinase and bisphosphoglycerate mutase activities [16].
• The reason why 1,3-bisphosphoglycerate is a better substrate for bisphosphoglycerate mutase than for monophosphoglycerate mutase (by a factor of about 30) is not yet apparent but presumably relates to the relative positioning of the two phospho-binding sites [17].

Analytical, diagnostic and therapeutic context of BPGM

• Consequently, in human BPGM, we replaced by site-directed mutagenesis the corresponding amino acid residue Gly13 with an Arg or a Lys [5].
• The ELISA was found to be practical for the determination of BPGM protein content in human erythrocytes [2].
• Molecular cloning and sequencing of the human erythrocyte 2,3-bisphosphoglycerate mutase cDNA: revised amino acid sequence [4].
• The identification of multiple molecular forms of human red cell phosphoglycerate mutase and 2,3-bisphosphoglycerate synthase by isoelectric focusing [18].
• Crystallization and preliminary X-ray diffraction studies of the human erythrocyte bisphosphoglycerate mutase [19].

References