Thermostability of the yolk protein, Lipovitellin
Biological Technician for the National Marine Fisheries Service
Francis Juanes (NRC), Joe Kunkel (Bio)
Marine teleosts are oviparous animals that utilize yolk proteins in the development of their embryos. A major source of nutrition is the yolk protein lipovitellin (Lv). Recent studies have also linked Lv to the osmotic uptake of water which allows fish to produce pelagic eggs. Despite Lv’s importance, the majority of research has centered on the yolk pre-cursor, vitellogenin (Vg). Vg is a good indicator of estrogenic toxins and easier to harvest than Lv since it resides in the blood stream. Lv must be extracted from an ovary or ovulated eggs and separated from other cellular components. Prior research showed that winter flounder, Pleuronectes americanus, Lvs, and several other fish species Lvs are thermally stable. This allowed us to isolate Lv via heat denaturation. We further quantified its thermal characteristics using differential scanning calorimetry (DSC). We compared Lvs from four different members of the pleuronectid family and found them to all have similar denaturation characteristics. This protein property has been conserved throughout the family. Knowledge of protein structure and stability characteristics will lead to a better understanding of the evolution of reproduction in marine teleosts.
Last updated August 5, 2010 by