Phosphoglucose isomerase isozymes and allozymes of the brown trout, Salmo trutta L.
1. In brown trout the Pgi-1 and Pgi-2 loci are predominantly expressed in white skeletal muscle; Pgi-3 being mainly expressed in most other tissues. 2. Total PGI activity determinations revealed that the allele formerly designated Pgi-2(65) is a null allele, Pgi-2(n). 3. Enzyme kinetic studies on the partially purified PGI homodimeric isozymes revealed that from 5 to 25 degrees C both PGI-1 and PGI-2 had significantly higher mean Km(F6P) values compared to PGI-3. 4. Distinct metabolic roles for the "muscle" (PGI-1, PGI-2) and "liver" (PGI-3) isozymes are proposed. 5. Significant Km (F6P) differences were found among the PGI-2 allozymes and among the PGI-3 allozymes.
Department of Zoology, Queen's University, Belfast, UK.
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Henry
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Ferguson
D000818:Animals; D005838:Genotype; D005956:Glucose-6-Phosphate Isomerase / Q000235:genetics / Q000378:metabolism*; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D008970:Molecular Weight; D009132:Muscles / Q000201:enzymology*; D009928:Organ Specificity; D012487:Salmonidae / Q000378:metabolism*; D013816:Thermodynamics; D014337:Trout / Q000378:metabolism*
D007527:Isoenzymes; D005956:Glucose-6-Phosphate Isomerase