| Autor: |
K.S. Keaton, John W. C. Bird, M.A. McElligott, F J Roisen, A.C. St John, J.A. Lee, G. Yorke |
| Rok vydání: |
1981 |
| Předmět: |
|
| DOI: |
10.1016/b978-0-08-027377-8.50006-3 |
| Popis: |
The characteristics of lysosomal proteinases were examined in cultured skeletal muscle cells. Rat myoblasts from the L6 myogenic line were cultured to provide three morphologically distinct populations: pre-fusion, post-fusion and non-fusion, a subclone that did not fuse even at high cell density. The lysosomal cathepsins B, D, H and L exhibited high specific activities in cell homogenates. Activities of cathepsin B and H were highest in post-fusion cells. The Michaelis-Menton constant (Km) was determined for cathepsins B, D and H and these values were the same in the different morphological populations. The lysosomal proteinases demonstrated classical distribution patterns after cell fractionation by differential centrifugation. Cathepsin B was partially purified from the L6 cells and shown to be capable of degrading native and denatured myosin. This myosin-degrading activity was completely blocked by leupeptin. All the L6 cultures exhibited active rates of protein degradation. Protein catabolism was most rapid in pre-fusion myoblasts. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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