Disease relevance of MPI

• Carbohydrate-deficient glycoprotein syndrome type Ib. Phosphomannose isomerase deficiency and mannose therapy [1].
• The phosphomannose-isomerase is encoded by the manA gene from Escherichia coli and catalyzes the conversion of mannose-6-phosphate to fructose-6-phosphate, an intermediate of glycolysis [2].
• The angiographic findings (significant >50% stenosis) and perfusion defects in MPI were compared with the severity of DTS [3].
• In the multivariate analysis only MPI (chi squared=22.6, P=0.018) and EF (chi squared=20.8, P=0.025) were significant independent predictors of heart failure or cardiac death [4].
• We investigated oxygen consumption (ml/kg/min) and hemodynamic response (peak heart rate-systolic blood pressure product) to individual exercise activities before and after exercise training in 22 male postmyocardial infarction patients (PMIP) [5].

Psychiatry related information on MPI

• This study provides psychometric data to support the use of the PMI and information about factors associated with use of active and passive coping strategies in pain sufferers [6].
• Use of the PMI for career counseling/decisions in nursing is not recommended, however, its use as an organizational development tool is endorsed [7].

High impact information on MPI

• An antiplatelet monoclonal antibody, PMI-1, reacts with glycoproteins (GP) GPIIb, free GPIIb, and the GPIIb-IIIa complex [8].
• The PMI-1 epitope was found to be contained within a 9-kDa staphylococcal V8 protease fragment of GPIIb, and such a fragment was predicted within the putative heavy-chain sequence [9].
• A cDNA clone that directs the synthesis of a fusion protein reactive with the PMI-1 antibody was isolated from a phage lambda gt11 expression library constructed with mRNA from an erythroleukemia (HEL) cell line [9].
• The oxygen consumption obtained for PMIP compared with available cumulative data on normal subjects is significantly variable, suggesting the need for caution when prescribing exercise for the PMIP based on energy costs of standard exercise measurements in normals [5].
• A relationship between the absence and presence of the heteropolymeric molecule, mannosephosphate isomerase (MPI), and pyruvate kinase (PK-3), assigned to chromosome 15, was established [10].

Chemical compound and disease context of MPI

• Phosphomannose isomerase deficiency: a carbohydrate-deficient glycoprotein syndrome with hepatic-intestinal presentation [11].
• DL41, a methionine auxotroph Escherichia coli strain, was transformed with a PMI expression plasmid and grown on an enriched selenomethionine-containing medium to high-cell densities [12].
• We studied the efficacy of aspirin and indomethacin therapy in relieving the discomfort of postmyocardial infarction pericarditis (PMIP) in two studies: (1) a retrospective evaluation of patients with symptomatic PMIP during a 5-year period and (2) a prospective, randomized, single-blind comparison of aspirin and indomethacin in similar patients [13].
• The Burkholderia cepacia bceA gene encodes a protein with phosphomannose isomerase and GDP-d-mannose pyrophosphorylase activities [14].
• METHODS: Nineteen male nonblockade recent postmyocardial infarction patients (PMIP), aged 60.7 +/- 6.5 yr, performed a graded exercise test on a motorized treadmill until volitional cessation or reaching any of the American College of Sports Medicine criteria [15].

Biological context of MPI

• Furthermore, mutational analysis of the MPI gene revealed two missense mutations, 419 T --> C (I140T) and 636 G --> A (R219Q), a single base substitution in intron 5, 670 + 9G --> A, as well as a polymorphism 1131A --> C (V377V) in both sibs [16].
• Phosphomannose isomerase catalyses the interconversion of fructose-6-P and mannose-6-P and has a critical role in the supply of D-mannose derivatives required for many eukaryotic glycosylation reactions [17].
• Based on amino acid sequence identity we propose a classification system for enzymes with phosphomannose-isomerase activity [17].
• Confirmation of the synteny of the human genes for mannose phosphate isomerase and pyruvate kinase and of their assignment to chromosome 15 [18].
• Electrophoretic patterns in F1 hybrid heterozygotes confirmed the monomeric structures of MPI and the esterase and the tetrametric structure of LDH in these fishes [19].

Anatomical context of MPI

• Phosphomannose-isomerase mRNA was found in all human tissues tested but was more highly expressed in heart, brain and skeletal muscle [17].
• The cell line isoenzymatic profiles were determined by using PGI, PGM, MPI and 6-PGDH systems, coinciding with patterns obtained from the same species and colony's pupae and adults [20].
• Synteny relationship between the human loci for hexosaminidase-a, mannose phosphate isomerase, and pyruvate kinase-3 studied in man-Chinese hamster somatic cell hybrids [21].
• Since phosphomannose isomerase is the rate-limiting step for mannose metabolism, our results suggest that mannose impairs erythrocyte defense against oxidants by causing ATP depletion and by impairing the regeneration of reduced pyridine nucleotides by the Embden-Meyerhof and pentose phosphate pathways [22].
• Platelet membranes contained significant amounts of the inducible fibrinogen receptor, glycoprotein (GP) IIb-IIIa, which exposes conformation-dependent LIBS1 and PMI-1 epitopes in response to fibrinogen-mimetic peptides GRGDSP and HHLG-GAKQAGDV [23].

Associations of MPI with chemical compounds

• These results suggest that the clinical manifestations of PMI deficiency, although serious in childhood, can improve with age, even without mannose therapy, and allow for a normal adult life [16].
• In contrast to some other bacterial GDP-mannose pyrophosphorylases, the mycobacterial enzyme was not multifunctional and did not have phosphomannose isomerase or phosphoglucose isomerase activity [24].
• Five enzymes, malate dehydrogenase, lactate dehydrogenase, mannose-phosphate isomerase, glucose-phosphate isomerase and phosphoglucomutase from seven putative species of Ostertagiinae were compared using starch-gel electrophoresis [25].
• A selection system based on the phosphomannose-isomerase gene (pmi) as a selectable marker and mannose as the selective agent was evaluated for the transformation of apple (Malus domestica Borkh.). Mannose is an unusable carbon source for many plant species [2].
• Furthermore, the binding of PMI-1 and anti-LIBS1 increased in response to GRGDSP, confirming a defect in agonist-mediated fibrinogen receptor activation rather than in fibrinogen binding or events distal to binding [26].

Physical interactions of MPI

• The peptide-antibody complex has an approximate Kd of 1.2 microM, which compares to a Kd of 0.95 microM for PMI-1 binding to GPIIb [9].

Other interactions of MPI

• New mutations were identified in MPI (Y129C) and ALG6 (G227E) [27].
• We therefore compared the frequency of this variant in 301 controls and in 101 CDG patients who carry known mutations in other genes involved in CDG, i.e. PMM2 (CDG-Ia; 91 patients) and MPI (CDG-Ib; 10 patients) [28].
• An abnormal serum transferrin isoelectric focusing (IEF) pattern and a reduced PMI activity confirmed the diagnosis of CDG-Ib [16].
• Three patients, including the one with the normal transferrin profile, did not have a deficiency of phosphomannomutase or phosphomannose isomerase (CDGS 1b) [29].
• The following syntenic groups were observed but could not be localized: GUK1-FH and MPI-PKM2 [30].

Analytical, diagnostic and therapeutic context of MPI

• The successful treatment of CDG Ib patients with oral mannose emphasises the paramount importance of early diagnosis of PMI deficiency [31].
• However, the brief screening version of MPI showed acceptable validity and reliability, except for rather low alpha values in sections 3 and 4 [32].
• CONCLUSION: Attenuation maps from CCS allow accurate AC of SPECT MPI images [33].
• The relationship between RV MPI and the end point of all-cause mortality, transplantation, or ventricular assist device placement was evaluated [34].
• METHODS: The MPI was measured in 63 consecutive patients (mean age 55 years, 49 men and 14 women) in sinus rhythm with an orthotopic heart transplantation for at least 1 year (mean 5.3 years) and in 63 age and sex-matched controls [4].

References