Biomaterial Database

[Effect of freezing-thawing on the activity of lactate dehydrogenase isoenzymes]. 1982

V I Lugovoi, and E L Volovel'skaia, and A M Grek

The activity of isolated M4- and H4-lactate dehydrogenase isoenzymes is studied after freezing in the saline solution to -8, -9.5, -23 and -30 degrees C. It is shown that the activity of H4-lactate dehydrogenase does not change, M4-lactate dehydrogenase being partially inactivated. It is demonstrated that a reduction in the M4-LDH activity is due to the effect of high salt concentrations on the freezing-out water from the solution and is an irreversible process. The fluorescence spectra of these isoenzymes are studied after freezing-thawing, and the interpretation of the observed changes in these spectra is suggested on the basis of possible alterations in the quaternary structure and sonformation of the enzyme molecule subunits. It is shown that the substrates and coenzymes of lactate dehydrogenase (NAD, NADH, pyruvate, lactate) completely or partially prevent the inactivation of M4-isoenzymes at freezing-thawing.

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
D007700	Kinetics	The rate dynamics in chemical or physical systems.
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
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D005615	Freezing	Liquids transforming into solids by the removal of heat.	Melting
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
D013552	Swine	Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).	Phacochoerus,Pigs,Suidae,Warthogs,Wart Hogs,Hog, Wart,Hogs, Wart,Wart Hog
D046911	Macromolecular Substances	Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.	Macromolecular Complexes,Macromolecular Compounds,Macromolecular Compounds and Complexes,Complexes, Macromolecular,Compounds, Macromolecular,Substances, Macromolecular