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ID 14889
file
creator
Togo, Summanuna H.
Maebuchi, Motohiro
Yokota, Sadaki
Bun-ya, Masanori
Kawahara, Akira
Kamiryo, Tatsuyuki
subject
Caenorhabditis elegans
catalase
3.3'-diaminobenzidine
peroxidase
peroxisomes
NDC
Biology
abstract
We purified catalase-2 of the nematode Caenorhabditis elegans and identified peroxisomes in this organism. The peroxisomes of C. elegans were not detectable by cytochemical staining using 3,3'-diaminobenzidine, a commonly used method depending on the peroxidase activity of peroxisomal catalase at pH 9 in which genuine peroxidases are inactive. The cDNA sequences of C. elegans predict two catalases very similar to each other throughout the molecule, except for the short C-terminal sequence; catalase-2 (500 residues long) carries a peroxisomal targeting signal 1-like sequence (Ser-His-Ile), whereas catalase-1 does not. The catalase purified to near homogeneity from the homogenate of C. elegans cells consisted of a subunit of 57 kDa and was specifically recognized by anti-(catalase-2) serum but not by anti-(catalase-1) serum. Subcellular fractionation and indirect immunoelectron microscopy of the nematode detected catalase-2 inside vesicles judged to be peroxisomes using morphological criteria. The purified enzyme (220 kDa) was tetrameric, similar to many catalases from various sources, but exhibited unique pH optima for catalase (pH 6) and peroxidase (pH 4) activities; the latter value is unusually low and explains why the peroxidase activity was undetectable using the standard alkaline diaminobenzidine- staining method. These results indicate that catalase-2 is peroxisomal and verify that it can be used as a marker enzyme for C. elegans peroxisomes.
journal title
European Journal of Biochemistry
volume
Volume 267
issue
Issue 5
start page
1307
end page
1312
date of issued
2000
publisher
Federation of European Biochemical Societies
issn
0014-2956
ncid
publisher doi
pubmed id
language
eng
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
publisher
rights
Copyright (c) 1990 Federation of European Biochemical Societies
relation is version of URL
http://dx.doi.org/10.1046/j.1432-1327.2000.01091.x
department
Graduate School of Integrated Arts and Sciences