Protease and peptidase activities in growing and sporulating cells and dormant spores of Bacillus megaterium.

AUTOR(ES)

Setlow, P

RESUMO

Peptidase and protease activities on many different substrates have been determined in several stages of growth of Bacillus megaterium. Extracts of log-phase cells, sporulating cells, and dormant spores of B. megaterium each hydrolyzed 16 different di- and tripeptides. The specific peptidase activity was highest in dormant spores, and the activity in sporulating cells and log-phase cells was about 1.2-fold and 2- to 3-fold lower, respectively. This peptidase acticity was wholly intracellular since extracellular peptidase activity was not detected throughout growth and sporulation. In contrast, intracellular protease activity on a variety of common protein substrates was highest in sporulating cells, and much extracellular activity was also present at this time. The specific activity of intracellular protease in sporulating cells was about 50- and 30-fold higher than that in log-phase cells and dormant spores, respectively. However, the two unique dormant spores proteins known to be the major species degraded during spore germination were degraded most rapidly by extracts of dormant spores, and slightly slower by extracts from log-phase or sporulating cells. The specific activities for degradation of peptides and proteins are compared to values for intracellular protein turnover during various stages of growth.

Documentos Relacionados

• Levels of cyclic GMP in dormant, germinated, and outgrowing spores and growing and sporulating cells of Bacillus megaterium.
• Levels of acetyl coenzyme A, reduced and oxidized coenzyme A, and coenzyme A in disulfide linkage to protein in dormant and germinated spores and growing and sporulating cells of Bacillus megaterium.
• Levels of H+ and other monovalent cations in dormant and germinating spores of Bacillus megaterium.
• Levels of oxidized and reduced pyridine nucleotides in dormant spores and during growth, sporulation, and spore germination of Bacillus megaterium.
• Purification and properties of phosphoglycerate phosphomutase from spores and cells of Bacillus megaterium.