ISSN:
0263-6484
Keywords:
Neurofibromatosis
;
human fibroblasts
;
alkaline phosphodiesterase I
;
tumourigenicity
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
Alkaline phosphodiesterase I from cultured fibroblasts from patients with neurofibromatosis was partially purified and characterized following extraction with Triton X-100, and fractionation with high-performance liquid chromatography. Some properties were compared with the enzyme extracted from normal-appearing fibroblasts. The isoelectric points of both the tumour and normal-appearing cell enzymes were 6·0. The enzyme required Zn2+ for its activity, was heat labile, and nicked superhelical covalently closed circular φX174 DNA. The activity was inhibited by GTP, DTT and EDTA. The native molecular weight of alkaline phosphodiesterase I was determined to be 430 000. No differences were found in properties of the tumour-derived and normal cell enzymes. On purification it was observed that the peak pattern of enzyme activity corresponded to that of 125 kDa protein, which was more abundant upon SDS-PAGE analysis in tumour cells than in normal cells. The most active fraction of isoelectric focusing, which was performed using disulfide cross-linked polyacrylamide gel, was used to produce an antibody. The bands of 125, 60 and 40 kDa were immuno-stained in tumour cell preparation. These results indicate that alkaline phosphodiesterase I, of which the molecular weight is probably 125 kDa, is over-expressed in tumour-derived fibroblasts from neurofibromatosis patients.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cbf.290110408
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