BIOL 193 |
| Proteins are vital to many functions of biological organisms such as muscle contraction and relaxation. It is known that different isoforms of a certain protein can each play a different physiological function. Consequently, the physiological properties of muscle are highly dependent on the various isoforms of several muscle proteins. We are characterizing one of these muscle proteins, parvalbumin, to understand how it controls numerous processes. Parvalbumin is a myoplasmic protein that aids in relaxation by releasing Mg2+ and binding free Ca2+, which reduces the intracellular concentration of the ion. Since Ca2+ plays a necessary role in contraction by binding to the regulatory protein troponin, a decrease in its intracellular concentration will result in relaxation of the muscle fiber. Although studies have shown differences in the Ca2+ dissociation constant (Kd) for parvalbumin from different fish species, there is presently no data on how Ca2+ and Mg2+ dissociation rates might vary between isoforms of a given fish species despite evidence that the relative expression of one isoform over the other has a large effect on relaxation rate in both sheepshead and rainbow trout. To address this issue, we are studying the Ca2+ and Mg2+ binding characteristics of parvalbumin isoforms in sheepshead and rainbow trout, fishes known to contain two isoforms of parvalbumin. Here we report on our isolation and characterization of two isoforms of parvalbumin from sheepshead (Archosargus probatocephalus) and rainbow trout (Oncorhynchus mykiss) and the role cation binding plays in muscle relaxation. |
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Frontiers in Chemical Biology
5:00 PM-7:00 PM, Wednesday, August 22, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Biological Chemistry |