The phosphorylase kinase deficiency (Phk) locus in the mouse: Evidence that the mutant allele codes for an enzyme with an abnormal structure
✍ Scribed by Stephen R. Gross; Margaret A. Longshore; Sharon Pangburn
- Publisher
- Springer
- Year
- 1975
- Tongue
- English
- Weight
- 1021 KB
- Volume
- 13
- Category
- Article
- ISSN
- 0006-2928
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✦ Synopsis
Female (I/St x C57BL/St)F~ mice heterozygous at the sex-linked phosphoryIase kinase deficiency locus (Phk) have phosphorylase kinase activities averaging 860/00 that of mice homozygous for the wild-type allele (C57BL/St), i.e., 72%o greater than the sum of one-half the activities of the parental strains. Approximately one-half the phosphorylase kinase activity in the (Ix C57BL)Ft muscle extracts had a stability at 42.5 C similar to that of the activity in C57BL extracts (ta/2 = 13.2 min); the other half of the activity in the F1 extracts was more labile (tl/2 = 3.9 rain). Two species of phosphorylase kinase activity in F~ muscle extracts were also differentiated with an antiserum prepared in guinea pigs against purified rabbit skeletal muscle phosphorylase kinase. This anti-serum cross-reacted with phosphorylase kinase in C57BL muscle extracts but did not cross-react with skeletal muscle extracts of mice hemi-or homozygous for the mutant allele (I/LnJ). The guinea pig antiserum precipitated 52%o as much protein from (Ix C57BL)Fa muscle extracts compared to those of C57BL. However, an antiserum prepared against purified rabbit skeletal muscle phosphorylase kinase in the goat cross-reacted with the mutant phosphorylase kinase. The ratio C57BL:(I x C57BL)Fl : I of immunoprecipitated protein from skeletal muscle extracts with this antiserum was 1:0.97:1.08. Polyacrylamide gel electrophoresis of the immunoprecipitates in the presence of 0.1% sodium dodecyIsulfate showed three subunits for mouse phosphorylase kinase with molecular weights of 139,000, 118,000, and 41,000; these values