scholarly journals The use of gel filtration to follow conformational changes in proteins. Conformational flexibility of bovine myelin basic protein.

1978 ◽  
Vol 253 (24) ◽  
pp. 8887-8893
Author(s):  
R.E. Martenson
Keyword(s):  
Myelin Basic Protein ◽  
Conformational Changes ◽  
Basic Protein ◽  
Gel Filtration ◽  
Conformational Flexibility

scholarly journals Purification and kinetic mechanism of S-adenosylmethionine: myelin basic protein methyltransferase from bovine brain

1988 ◽  
Vol 250 (1) ◽  
pp. 221-226 ◽  
Author(s):  
P R Young ◽  
C M Waickus
Keyword(s):  
Myelin Basic Protein ◽  
Basic Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
High Specificity ◽  
Kinetic Mechanism ◽  
Bovine Brain ◽  
Tryptic Cleavage ◽  
Protein Methyltransferase

The enzyme S-adenosylmethionine (AdoMet): myelin basic protein (MBP) methyltransferase was purified 250-fold from bovine brain with an overall yield of 130%, relative to crude supernatant. The purification involves acid-base and (NH4)2SO4 precipitation, chromatography over Sephadex G-100 and DEAE-cellulose, followed by preparative isoelectric focusing. The enzyme has a pI of 5.60 +/- 0.05, and the Mr is estimated to be between 71,000 (from SDS/polyacrylamide-gel electrophoresis) and 74,500 (from gel filtration). The enzyme is stable at 37 degrees C for over 2 h, is stable frozen and does not require metal ions or reductants. The enzyme shows a high specificity for MBP and does not accept polyarginine as a substrate; F1 histone is methylated at 37% of the rate of MBP. Methylation occurs on an arginine residue in a single h.p.l.c.-resolvable peptide from the tryptic cleavage of MBP. Simple saturation kinetics are observed with respect to both substrates, with Km values of 18 microM and 32 microM for MBP and AdoMet respectively. The simplest kinetic mechanism that is consistent with the data requires ordered rapid-equilibrium binding, with AdoMet as the first substrate. The enzyme isolated in this work is different, both physically and kinetically, from the histone-specific arginine methyltransferases described by other workers. A new, simple, assay system for the methylation of MBP is described.

N.M.R. Studies of Myelin Basic Protein. III. Interactions of the Protein with Lipid Micelles by 1H and 31P N.M.R.

1979 ◽  
Vol 32 (12) ◽  
pp. 2631 ◽  
Author(s):  
LAT Littlemore ◽  
RW Ledeen
Keyword(s):  
Myelin Basic Protein ◽  
Conformational Changes ◽  
Basic Protein ◽  
Polypeptide Chain ◽  
Lipid Binding ◽  
Bovine Brain ◽  
Gm1 Ganglioside ◽  
Spectral Changes ◽  
Central Regions ◽  
Lipid Micelles

The interactions of bovine myelin basic protein with bovine brain GM1 ganglioside and with lysophosphatidylcholine have been followed by 1H and 31P N.M.R. The effect of the binding of lipid on the protein spectrum could be followed in methyl peaks due to methionine and NG-methylarginine and in peaks from aromatic side chains. Both lipids caused broadening of methyl resonances from methionine-20, the unique NG-methylarginine and phenylalanines. The N.M.R. spectral changes on interaction of peptides derived from N-terminal and C-terminal halves of the protein with lysolecithin indicated that the lipid binding was associated with conformational changes involving the central regions of the polypeptide chain and the methylarginine residue. The 31P spectra suggest that the average phosphate group in lysophosphatidylcholine becomes more mobile as a result of binding of basic protein to the lipid micelle.

scholarly journals Igg-Dependent Hydrolysis of Myelin Basic Protein of Patients with Different Courses of Schizophrenia

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Daria A. Parshukova ◽  
Liudmila P. Smirnova ◽  
Elena G. Kornetova ◽  
Arkadiy V. Semke ◽  
Valentina N. Buneva ◽  
...  
Keyword(s):  
Myelin Basic Protein ◽  
Basic Protein ◽  
Specific Activity ◽  
Paranoid Schizophrenia ◽  
Gel Filtration ◽  
Maximal Activity ◽  
Disease Course ◽  
Healthy Individuals ◽  
Acute Schizophrenia ◽  
Hydrolysis Of

The level hydrolysis of myelin basic protein (MBP) by IgG in patients with schizophrenia was studied depending on the clinical features and course of the disease. The patients were grouped according to type of schizophrenia and type of disease course. We found that IgGs isolated and purified from sera of schizophrenia patients’ blood hydrolyses human MBP, and the level of this hydrolysis significantly exceeds that of healthy individuals. Detection of protease activity corresponding only to intact IgGs in polyacrylamide gel fragments, together with data of gel filtration of antibodies under conditions of “acid shock” (concordance of optical density profile of IgG with profile of MBP-hydrolyzing activity) and with the absence of any other proteins and bands in gradient SDS-PAGE and in PVDF membrane provides direct evidence that the IgGs from the schizophrenia patients have MBP-hydrolyzing activity. The antibodies-specific proteolytic activity of patients with acute schizophrenia (1.026 [0.205; 3.372] mg MBP/mg IgG/h) significantly exceeds the activity of IgG in patients in remission (0.656 [0.279; 0.873] mg MBP/mg IgG/h) and in healthy individuals (0.000 [0.00; 0.367] mg MBP/mg IgG/h). When comparing the specific activity in patients with different types of disease course, we have found that patients with a continuous course of paranoid schizophrenia (1.810 [0.746; 4.101 mg MBP/mg IgG/h]) had maximal activity values. It can be assumed that the increase in the activity of MBP-hydrolyzing antibodies is due to the activation of humoral immunity in acute schizophrenia.

Co-purification of bone resorbing activity and adenylate cyclase stimulating activity from human tumours associated with the humoral hypercalcaemia of malignancy

1987 ◽  
Vol 114 (1) ◽  
pp. 18-26 ◽  
Author(s):  
Chohei Shigeno ◽  
Itsuo Yamamoto ◽  
Shegiharu Dokoh ◽  
Megumu Hino ◽  
Jun Aoki ◽  
...  
Keyword(s):  
Bone Resorption ◽  
High Performance ◽  
Basic Protein ◽  
Gel Filtration ◽  
Exchange Chromatography ◽  
Protein Factor ◽  
Human Tumours ◽  
Acid Stable ◽  
Bone Resorbing Activity

Abstract. We have partially purified a tumour factor capable of stimulating both bone resorption in vitro and cAMP accumulation in osteoblastic ROS 17/2 cells from three human tumours associated with humoral hypercalcaemia of malignancy. Purification of tumour factor by sequential acid urea extraction, gel filtration and cation-exchange chromatography, reverse-phase high performance liquid chromatography followed by analytical isoelectric focussing provided a basic protein (pI > 9.3) with a molecular weight of approximately 13 000 as a major component of the final preparation which retained both the two bioactivities. Bone resorbing activity and cAMP-increasing activity in purified factor correlated with each other. cAMP-increasing activity of the factor was heat- and acid-stable, but sensitive to alkaline ambient pH. Treatment with trypsin destroyed cAMP-increasing activity of the factor. Synthetic parathyroid hormone (PTH) antagonist, human PTH-(3– 34) completely inhibited the cAMP-increasing activity of the factor. The results suggest that this protein factor, having its effects on both osteoclastic and osteoblastic functions, may be involved in development of enhanced bone resorption in some patients with humoral hypercalcaemia of malignancy.

scholarly journals Myelin basic protein enhances axonal regeneration from neural progenitor cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhengjian Yan ◽  
Lei Chu ◽  
Xiaojiong Jia ◽  
Lu Lin ◽  
Si Cheng
Keyword(s):  
Myelin Basic Protein ◽  
Neurite Outgrowth ◽  
Progenitor Cells ◽  
Axonal Regeneration ◽  
Neural Progenitor Cells ◽  
Basic Protein ◽  
Neural Progenitor ◽  
Dependent Manner ◽  
Cord Injury

Abstract Introduction Stem cell therapy using neural progenitor cells (NPCs) shows promise in mitigating the debilitating effects of spinal cord injury (SCI). Notably, myelin stimulates axonal regeneration from mammalian NPCs. This led us to hypothesize that myelin-associated proteins may contribute to axonal regeneration from NPCs. Methods We conducted an R-based bioinformatics analysis to identify key gene(s) that may participate in myelin-associated axonal regeneration from murine NPCs, which identified the serine protease myelin basic protein (Mbp). We employed E12 murine NPCs, E14 rat NPCs, and human iPSC-derived Day 1 NPCs (D1 hNPCs) with or without CRISPR/Cas9-mediated Mbp knockout in combination with rescue L1-70 overexpression, constitutively-active VP16-PPARγ2, or the PPARγ agonist ciglitazone. A murine dorsal column crush model of SCI utilizing porous collagen-based scaffolding (PCS)-seeded murine NPCs with or without stable Mbp overexpression was used to assess locomotive recovery and axonal regeneration in vivo. Results Myelin promotes axonal outgrowth from NPCs in an Mbp-dependent manner and that Mbp’s stimulatory effects on NPC neurite outgrowth are mediated by Mbp’s production of L1-70. Furthermore, we determined that Mbp/L1-70’s stimulatory effects on NPC neurite outgrowth are mediated by PPARγ-based repression of neuron differentiation-associated gene expression and PPARγ-based Erk1/2 activation. In vivo, PCS-seeded murine NPCs stably overexpressing Mbp significantly enhanced locomotive recovery and axonal regeneration in post-SCI mice. Conclusions We discovered that Mbp supports axonal regeneration from mammalian NPCs through the novel Mbp/L1cam/Pparγ signaling pathway. This study suggests that bioengineered, NPC-based interventions can promote axonal regeneration and functional recovery post-SCI.

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