The conversion of inactive phosphorylase to phosphorylase b and phosphorylase a in lobster muscle extract
Cowgill, R.W.; Cori, C.F.
Journal of Biological Chemistry 216(1): 133-140
ISSN/ISBN: 0021-9258 PMID: 13252013 Accession: 025715304
Extracts prepared from the tail muscle of lobsters maintained in a tank contain an inactive form of phosphorylase which is converted to phosphorylase b and then to phosphorylase a during incubation of the extract. The average increase in phosphorylase activity in 14 extracts was 3.5-fold. Temperature, adenosine-5-phosphate, fluoride, and a number of detergents were found to accelerate this transformation. Versene inhibited the reaction completely. Addition of rabbit muscle phosphorylase b to these extracts results in its conversion to phosphorylase a. Extracts prepared from muscle of dormant lobsters kept out of water under refrigeration showed initially a higher phosphorylase content and no rise on incubation. A frog muscle extract showed a nearly 2-fold rise in phosphorylase activity during incubation, while extracts from rat and rabbit muscle showed only small changes.