HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Mo, Y. Articles by Gracy, R. W. Search for Related Content PubMed PubMed Citation Articles by Mo, Y. Articles by Gracy, R. W. Social Bookmarking                      What's this?

JBC, Vol. 250, Issue 17, 6747-6755, Sep, 1975

Isolation and characterization of tissue-specific isozymes of glucosephosphate isomerase from catfish and conger

Y. Mo, C. D. Young and R. W. Gracy

In teleosts glucosephosphate isomerase exists as two tissue-specific isozymes. Most tissues contain the more acidic liver-type isozyme, while white muscle contains the more basic isozyme; and a few tissues contain both the liver- and muscle-type isozymes as well as a hybird. The isozymes were isolated from catfish liver and muscle and from conger muscle and shown to be homogeneous by polyacrylamide gel electrophoresis, isoelectric focusing, analytical ultracentrifugation, and rechromatography. Both isozymes are of molecular weight 132,000 (S020,w = 7.0 S) and composed of two subunits of Mr approximately 65,000. The muscle and liver isozymes were shown to have distinct isoelectric points (catfish liver = 6.2; muscle = 7.0) and amino acid compositions. Tryptic peptide maps, after S-carboxymethylation and carbamylation, revealed several distinct differences in the primary structures of the isozymes. Although the isozymes could also be distinguished on the basis of their stabilities, most of their basic catalytic properties were found to be similar. A conger was obtained which was heterozygous for the variant allele at the muscle-glucosephosphate isomerase locus. A comparison of the variant conger muscle isozyme with the wild type revealed a single altered peptide, suggesting a point mutation. The structure-function studies, as well as the genetic studies, clearly establish that the two types of isozymes are of independent genetic origin.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				Y.-J. Sun, C.-C. Chou, W.-S. Chen, R.-T. Wu, M. Meng, and C.-D. Hsiao The crystal structure of a multifunctional protein: Phosphoglucose isomerase/autocrine motility factor/neuroleukin PNAS, May 11, 1999; 96(10): 5412 - 5417. [Abstract] [Full Text] [PDF]