Nejvíce citovaný článek - PubMed ID 402306
Intracellular proteolytic activity during sporulation of Bacillus megaterium
Germinated spores of Bacillus megaterium were mutagenized with ethyl methanesulphonate and spread on test agar with caseinate. Colonies with altered proteolytic zones or morphology were isolated and tested in liquid media. The mutants can be divided into four groups: A) those producing more proteinase in both growth and sporulation media, B) those producing the same amount of the enzyme in growth medium but higher amount in sporulation medium, C) those producing less proteinase in the growth medium and more in the sporulation one, D) those producing less or no enzyme. Clones of the first three groups were phenotypically asporogenic. All mutants producing more enzyme during growth retained their sensitivity to repression by amino acids. Isolation of mutants of types B) and C) supports the idea of differences in the control of proteinase synthesis during growth and during sporulation.
- MeSH
- Bacillus megaterium enzymologie genetika růst a vývoj MeSH
- endopeptidasy biosyntéza MeSH
- kultivační média MeSH
- mutace * MeSH
- neprilysin MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- endopeptidasy MeSH
- kultivační média MeSH
- neprilysin MeSH
Abnormal proteins synthesized in the presence of ethionine were degraded more rapidly than the normal ones in cell-free extracts of ethanol-grown yeast. The denatured proteins, however, were degraded in preference to their native counterparts which were either normal or abnormal.
During cultivation of Bacillus megaterium at 42 degrees C the amount of the exocellular protease produced by growing cells sharply decreases as compared with temperatures of 28 and 35 degrees C. Within the above range the growth rate and incorporation of amino acids increase with increasing temperature. The culture adapted to 42 degrees C does not produce more proteinase at this temperature than the non-adapted culture. The high temperature does not induce accumulation of the enzyme in the cells. Total protein excretion was slightly lower at 42 degrees C than at 28 and 35 degrees C.
- MeSH
- Bacillus megaterium enzymologie MeSH
- bakteriální proteiny metabolismus MeSH
- endopeptidasy biosyntéza MeSH
- vysoká teplota MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- bakteriální proteiny MeSH
- endopeptidasy MeSH
Synthesis of exocellular metalloprotease and cellular and exocellular proteins in the sporogenic strain Bacillus megaterium J-27 and asporogenic strain KM 1 was investigated. Both organisms excrete the enzyme into the medium during growth and during the stationary phase. In the asporogenic strain the excretion decreases at the end of the exponential phase. In the sporogenic strain it continues during the transition to the stationary phase at the original rate and proteolytic activity in the medium increases two to three times during 2 h after the end of the exponential phase. Both organisms synthesize relatively more exocellular proteins during the exponential phase than during the stationary phase. The proportion of exocellular protein synthesized during the exponential phase does not exceed 3 % of total proteins, during the stationary phase this proportion usually decreases to less than 1 %.
- MeSH
- Bacillus megaterium růst a vývoj metabolismus MeSH
- bakteriální proteiny biosyntéza MeSH
- druhová specificita MeSH
- endopeptidasy biosyntéza MeSH
- metaloendopeptidasy MeSH
- spory bakteriální MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- bakteriální proteiny MeSH
- endopeptidasy MeSH
- metaloendopeptidasy MeSH
- MeSH
- Bacillus megaterium růst a vývoj metabolismus MeSH
- bakteriální proteiny metabolismus MeSH
- kinetika MeSH
- kultivační média MeSH
- mutace MeSH
- proteasy metabolismus MeSH
- spory bakteriální MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- bakteriální proteiny MeSH
- kultivační média MeSH
- proteasy MeSH
The rate of protein turnover in asporogenic Bacillus megaterium decreases continuously during incubation in a sporulation medium. The capability of equilibration of external amino acids with amino acids in the metabolic pool of non-growing cells was retained for at least 5 h. Leucine, while repressing the synthesis of the exocellular protease, does not significantly influence the course of protein degradation in vivo. Transfer of non-growing cells after 4 h to a fresh sporulation medium does not influence the rate of protein degradation. The gradual decrease of the rate of protein turnover in non-growing cells of the asporogenic variant is thus not an artifact caused by a decreased uptake of amino acids by cells or by conditions under which the protein turnover is determined.
- MeSH
- aminokyseliny metabolismus MeSH
- Bacillus megaterium růst a vývoj metabolismus MeSH
- bakteriální proteiny metabolismus MeSH
- kinetika MeSH
- kultivační média MeSH
- leucin metabolismus MeSH
- spory bakteriální MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- aminokyseliny MeSH
- bakteriální proteiny MeSH
- kultivační média MeSH
- leucin MeSH
Functional half-life of the exocellular protease mRNA was determined in in exponentially growing and stationary cells of the asporogenic strain of Bacillus megaterium KM and in the sporogenic strain of B. megaterium 27 during sporulation. No reserve of the protease mRNA could be detected in the cells and the half-lives were determined to be 6--7 min in the exponential and stationary cells of B. megaterium KM and 7.5--8.5 min in B. megaterium 27. The mean half-life of mRNA for cell proteins was determined to be 3.5--4.5 min. Thus, as compared with the mean half-life of mRNA for cell proteins that of mRNA for the exocellular protease is slightly longer.
- MeSH
- Bacillus megaterium metabolismus fyziologie MeSH
- bakteriální proteiny biosyntéza MeSH
- bakteriální RNA biosyntéza metabolismus MeSH
- daktinomycin farmakologie MeSH
- genetická transkripce účinky léků MeSH
- messenger RNA metabolismus MeSH
- poločas MeSH
- proteasy biosyntéza MeSH
- spory bakteriální MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- bakteriální proteiny MeSH
- bakteriální RNA MeSH
- daktinomycin MeSH
- messenger RNA MeSH
- proteasy MeSH
