Biomaterial Database

Lactate dehydrogenase of Xenopus laevis laevis and Xenopus borealis depends on a multiple gene system. 1982

J Wolff, and H R Kobel

Lactate dehydrogenase isozymes have been reinvestigated in Xenopus laevis laevis and Xenopus borealis. High resolution zymograms of various organs demonstrate that in both species the LDH isozymes are governed basically by a three-gene system: Ldh-a coding for positively charged polypeptide, and Ldh-b and Ldh-c for negatively charged polypeptides (at pH 8.9). These three LDH subunits when assembled in tetramers show differential sensitivity to heat inactivation; the C4 homotetramer is the most labile isozyme. Xenopus is thus similar to Osteichthyes, birds, and mammals that also have a three-gene system for LDH. With respect to tissue specific isozyme expression, Xenopus resembles the more primitive families of bony fish. Superimposed on this three-gene system is a probable gene duplication for both LDH-a and Ldh-b. Heterotetrameric isozymes are formed between the various subunits leading to multibanded zymograms with a total of at least 21 distinct zones of LDH activity. The expression of genes is tissue specific not only for the basic genes, but also for their presumed duplicates. Since both species of Xenopus are ancient tetraploids, duplication of Ldh genes is not surprising.

UI	MeSH Term	Description	Entries
D007527	Isoenzymes	Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.	Alloenzyme,Allozyme,Isoenzyme,Isozyme,Isozymes,Alloenzymes,Allozymes
D007770	L-Lactate Dehydrogenase	A tetrameric enzyme that, along with the coenzyme NAD+, catalyzes the interconversion of LACTATE and PYRUVATE. In vertebrates, genes for three different subunits (LDH-A, LDH-B and LDH-C) exist.	Lactate Dehydrogenase,Dehydrogenase, L-Lactate,Dehydrogenase, Lactate,L Lactate Dehydrogenase
D005796	Genes	A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.	Cistron,Gene,Genetic Materials,Cistrons,Genetic Material,Material, Genetic,Materials, Genetic
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014018	Tissue Distribution	Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.	Distribution, Tissue,Distributions, Tissue,Tissue Distributions
D014981	Xenopus	An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.