{"title":"Rabbit kidney cortex phosphorylase phosphatases: evidence for complexes between high molecular weight forms and heat-stable inhibitor proteins.","authors":"R L Mellgren, K K Schlender","doi":"","DOIUrl":null,"url":null,"abstract":"<p><p>Two forms of high molecular weight phosphorylase phosphatase have been partially resolved by gel filtration chromatography of rabbit kidney cortex extracts. Two heat-stable inhibitor proteins co-eluted with the phosphatase peaks. Phosphorylase phosphatase and heat-stable inhibitor activity also co-migrated on gel electrophoresis of cortex extracts. When extracts were heated to 95 degrees for 5 minutes prior to gel filtration or electrophoresis, phosphorylase phosphatase inhibitor activity eluted at a lower molecular weight and a higher mobility, respectively. Storing cortex extracts at -20 degrees for 6 months resulted in partial conversion of both phosphatase and inhibitor activities to lower molecular weight forms which co-eluted on gel filtration. The two inhibitor peaks from gel filtration chromatography were heat-treated and characterized. Both inhibitor peaks had molecular weight of 25,000 to 35,000. The inhibitory activity of one of the peaks was increased about 3.5-fold by incubation with cyclic AMP-dependent protein kinase and ATP, and required higher concentrations of TCA to be precipitated. Hence, one of the inhibitor peaks resembled rabbit muscle inhibitor -1, while the other peak may represent an inhibitor similar to rabbit muscle inhibitor -2. These results represent the first indication that low molecular weight heat-stable inhibitor proteins may be bound to high molecular weight phosphorylase phosphatases in the cell.</p>","PeriodicalId":15497,"journal":{"name":"Journal of cyclic nucleotide research","volume":"8 1","pages":"27-37"},"PeriodicalIF":0.0000,"publicationDate":"1982-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of cyclic nucleotide research","FirstCategoryId":"1085","ListUrlMain":"","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Two forms of high molecular weight phosphorylase phosphatase have been partially resolved by gel filtration chromatography of rabbit kidney cortex extracts. Two heat-stable inhibitor proteins co-eluted with the phosphatase peaks. Phosphorylase phosphatase and heat-stable inhibitor activity also co-migrated on gel electrophoresis of cortex extracts. When extracts were heated to 95 degrees for 5 minutes prior to gel filtration or electrophoresis, phosphorylase phosphatase inhibitor activity eluted at a lower molecular weight and a higher mobility, respectively. Storing cortex extracts at -20 degrees for 6 months resulted in partial conversion of both phosphatase and inhibitor activities to lower molecular weight forms which co-eluted on gel filtration. The two inhibitor peaks from gel filtration chromatography were heat-treated and characterized. Both inhibitor peaks had molecular weight of 25,000 to 35,000. The inhibitory activity of one of the peaks was increased about 3.5-fold by incubation with cyclic AMP-dependent protein kinase and ATP, and required higher concentrations of TCA to be precipitated. Hence, one of the inhibitor peaks resembled rabbit muscle inhibitor -1, while the other peak may represent an inhibitor similar to rabbit muscle inhibitor -2. These results represent the first indication that low molecular weight heat-stable inhibitor proteins may be bound to high molecular weight phosphorylase phosphatases in the cell.