Myosin light chain phosphorylation in frog heart

Kate Bárány: a life of science, teaching, and service

We celebrate the lives of Michael and Kate Bárány in this issue of the Journal of Muscle Research and Cell Motility. Kate and Michael died within weeks of each other in 2011. Joe Chalovich has written about Michael and we write about Kate. As emphasized by Joe, Kate, and Michael were remarkable individuals who survived the Holocaust, the Hungarian revolution, and emerged from as much adversity as one might imagine to become productive scientists, educators, citizens, and symbols of the durability of the human spirit. They present their own story in an essay (Bárány and Bárány 2000) published in a monograph "Selected Topics in the History of Biochemistry." Rather than repeating much of the list of scientific achievements chronicled in these papers, we focus here on Kate, especially in her role as an individual and partner in science, while at the same time being an accomplished teacher, and a champion of women in science.

Polyacrylamide gel electrophoretic methods in the separation of structural muscle proteins

Polyacrylamide gel electrophoresis plays a major role in analyzing the function of muscle structural proteins. This review describes one- and two-dimensional gel electrophoretic methods for qualitative and quantitative investigation of the muscle proteins, with special emphasis on determination of protein phosphorylation. The electrophoretic studies established the subunit structures of the muscle proteins, characterized their multiple forms, revealed changes in subunit composition or shifts in isoform distribution of specific proteins during development, upon stimulation or denervation of the muscle. Protein phosphorylation during muscle contraction is preferentially studied by two-dimensional gel electrophoresis. The same method demonstrated protein alterations in human neuromuscular diseases.

Myosin light chain phosphorylation during contraction of turtle heart

The phosphorylation of myosin P-light chain was determined during the contraction cycle of turtle heart beating 5--8 times/min at 5 degrees C. The hearts were freeze-clamped either in systole or diastole, then homogenized and washed in strong acids in order to completely inhibit myosin light chain kinase and phosphatase and isolate the total P-light chain of the heart. The phospho and dephospho forms of P-light chain were separated by two-dimensional gel electrophoresis and were quantitated by densitometry. Alternatively, the hearts were perfused with 32P and the incorporation of [32P]phosphate into the P-light chain was determined. Both methods demonstrated that in hearts frozen in systole more P-light chain was phosphorylated than in hearts frozen in diastole.