ISSN:
1432-0991
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract Both plasmid pPFC4, which contains 10.6 kb, and a derivative of pPFC4—viz., pPFC4-4.6—which contains 4.6 kb ofPseudomonas fluorescens subsp.cellulosa DNA, direct the synthesis of six distinct endoglucanases inEscherichia coli. Two of these enzymes were purified to homogeneity in a single step by means of anion exchange HPLC. One enzyme has a molecular weight of 30.0 ± 1.0 kDa, an isoelectric point of 7.5, and a specific activity of 3470 U of activity/mg of protein, whereas the other has a molecular weight of 38.5 ± 1.0 kDa, an isoelectric point of 6.7, and a specific activity of 18,050 U of activity/mg of protein. On the basis of the amino acid composition, the 38.5 kDa enzyme appears to be a modified version of the 30.0 kDa enzyme. Thus, the multiplicity of endoglucanases produced inE. coli/pPFC4-4.6 cells may be owing to the posttranslational modification of a smaller number of primary translation products.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02091916
