Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:3.1.4.37 (
CNPase
)
539
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Oligodendrocytes generate myelin as extensions of the plasma membrane. Myelin has been well characterized, yet little is known concerning oligodendrocyte plasma membrane. We have developed a reproducible method for the isolation of an oligodendrocyte plasma membrane-rich fraction (F2.2). F2.2 has a 25-fold enrichment in K+-dependent p-nitrophenyl phosphatase, a plasma membrane marker. Impurities are composed of Golgi elements (8-12%), microsomes (4-6%), and lysosomal membranes (1-5%). Our starting material was oligodendrocytes kept in culture in a nonattached state for 3 to 5 d. After disrupting the cells and removing nuclei (P1), the supernatant (SP1) was fractionated on a self-generating 20% Percoll gradient into three bands: F1, F2, and F3. F1 had only 3% of the applied protein and was not characterized. F2, with 11% of the protein, was fivefold enriched in plasma membrane. F3 had 27% of initial protein; it consisted of a crude mitochondrial and lysosomal fraction. F2 was further purified by first washing it hypotonically, treating it with
Mg2+
, and then fractionating it on a Ficoll step gradient that yielded F2.2 at the interphase. Morphologically F2.2 comprises 1) membranous sheets, often with more than one membrane in close apposition; 2) membrane vesicles of various sizes and shapes frequently filled with amorphous material; 3) Golgi elements; and 4) unrecognizable profiles. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis protein profile of F2.2 reveals
CNPase
as a major component in agreement with the high
CNPase
specific activity (3,860 mumol/mgP/h) found in F2.2. Other significant polypeptides have Mr = 170,000, 135,000, 108,000, 80,000, 53,000, 38,500, 32,000, and 22,200.
...
PMID:Plasma membrane of cultured oligodendrocytes: I. Isolation, purification, and initial characterization. 297 38
A procedure was developed for the detection of
2',3'-cyclic nucleotide 3'-phosphohydrolase
in myelin. This assay was sufficiently to detect the low levels of
2',3'-cyclic nucleotide 3'-phosphohydrolase
in human erythrocytes. The
2',3'-cyclic nucleotide 3'-phosphohydrolase
of human erythrocytes was determined to be exclusively associated with the inner (cytosolic) side of the membrane. Leaky ghosts and resealed ghosts were assayed for
2',3'-cyclic nucleotide 3'-phosphohydrolase
(Ca2+/
Mg2+
)-ATPase, and acetylcholinesterase activity, and the
2',3'-cyclic nucleotide 3'-phosphohydrolase
profile is the same as that of the (Ca2+/
Mg2+
)-ATP, an established inner membrane marker.
...
PMID:Specific localization of 2',3'-cyclic nucleotide 3'-phosphohydrolase, (Ca2+/Mg2+)-ATPase, and acetylcholinesterase in human erythrocyte membrane. 611 15
