title: Analysis of smooth muscle myosin phosphorylation with native pyrophosphate gels and its application to studies on myosin phosphorylation in contracting smooth muscle.
abstract: Gizzard smooth muscle myosin, the 20,000 Mr light chain (L20) of which had been phosphorylated in vitro with a calmodulin-myosin light chain kinase system, was separated into 5 isolated bands in a pyrophosphate polyacrylamide gel. Their mobilities were in the following order: myosin with 2 unphosphorylated L20 (GM) less than myosin with 1 unphosphorylated and 1 mono-phosphorylated L20 (GMP1) less than myosin with 2 mono-phosphorylated L20 (GMP2) less than myosin with 1 mono-phosphorylated and 1 di-phosphorylated L20 (GMP3) less than myosin with 2 di-phosphorylated L20 (GMP4). We used this pyrophosphate polyacrylamide gel electrophoresis to analyze the phosphorylated state of taenia coli smooth muscle during K+-induced contraction. During the initial 2 min contraction, phosphorylated forms corresponding to GMP1 and GMP2 were detected in addition to the unphosphorylated form.
mesh_terms: D000818:Animals; D002645:Chickens; D011756:Diphosphates; D004591:Electrophoresis, Polyacrylamide Gel; D005895:Gizzard, Avian / Q000032:analysis; D006168:Guinea Pigs; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000032:analysis* / Q000502:physiology; D009218:Myosins / Q000032:analysis*
chemical_list: D011756:Diphosphates; D009218:Myosins