Functional and adaptive significance of differentially expressed lactate dehydrogenase isoenzymes in tissues of four obligatory air-breathing Channa species

Abstract

This study investigates the differential expression of lactate dehydrogenase (LDH) isoenzymes in the genus Channa using PAGE. With the help of obligate air-breathing, all of the selected species can sustain water deprivation to varying degrees. In subunit composition and higher electrophoretic mobility of LDH-A4, the profiles of channid species were similar to other teleosts documented in the literature. However, inter-and intra-species differences, with particular reference to aerobic/anaerobic metabolic options, existed. Whereas glycolysis in Channa punctata appears to depend largely on aerobic LDH-B and partly on anaerobic LDH-A, metabolism in C. gachua, C. striata and C. marulius depends exclusively on the activity of anaerobic LDH-A. Expression of the third locus Ldh-C was recorded in the eyes of C. marulius, in addition to C. gachua. Heat inactivation experiments reveal species differences between LDH isoenzymes and a general order of the relative stabilities: LDH-C > LDH-B > LDH-A. Metabolic and evolutionary implications of the findings have also been discussed.

Lactate Dehydrogenase Isoenzymes in Tissues of Carnivorous Mammals During Postnatal Ontogeny

“…Лактатдегидрогеназа (ЛДГ) широко используется в качестве модельного фермента при изучении биохимических адаптаций [Hochachka, Somero, 2002;Rossignol et al, 2003;Тютюнник и др., 2005;Ahmad, 2009;Sergina et al, 2015;Унжаков, Тютюнник, 2016]. Молекула фермента представляет собой тетрамер, состоящий из двух типов субъединиц H (от англ.…”

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“…Previously (Hasnain and Jabeen, 2001;Ahmad and Hasnain, 2006). LDH isozymes, myofibrillar proteins and polymorphic myosin heavy chain of channids also exhibit functional plasticity (Ahmad and Hasnain, 2005;Arif et al, 2007;Ahmad, 2009;Ahmad and Hasnain, 2013). While other fishes may temporarily switch on to expression of heat shock proteins (Kayhan and Duman, 2010), thermostability of proteins appears to be inherent characteristic of airbreathing channids (Hasnain and Jabeen, 2001;Ahmad et al, 2007a;Arif et al, 2007).…”