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Folia Microbiologica

, 6:231 | Cite as

Localization of proteases in cells ofEscherichia coli andBacillus megaterium

  • J. Chaloupka
Article

Summary

  1. (1)

    The localization of proteases in the cells ofBacillus megaterium andEscherichia coli was investigated. The first named species is a typical proteolytic micro-organism, the second does not excrete any protease into the medium.

     
  2. (2)

    In both species, some 30% total enzyme activity was released into the medium during the formation of the protoplasts or sphaeroplasts. A part of the released protease seems to originate from the disrupted protoplasts.

     
  3. (3)

    The enzyme occurring inside the protoplasts was distributed practically uniformly in both the species between the fraction sedimenting at 10,000 g and the supernatant.

     
  4. (4)

    InEscherichia coli, the enzyme fraction found in the ghosts amounts to 45%, inBacillus megaterium to 38%.

     
  5. (5)

    A more detailed study of the distribution of the enzyme was carried out inEscherichia coli sphaeroplasts. The ribo-some fraction, sedimenting at 105,000 g., was found to contain about 10% of the total enzyme activity. The cytoplasm contained some 60% and the plasma membrane fraction some 30%. The enzyme fraction found in the cytoplasm was increased somewhat by washing with buffer, due to solubilization of protease in the ghosts.

     
  6. (6)

    Ethylenediamine tetraacetic acid or urea acting on the ribosomes brought about no increase in the proteolytic activity. The former decreased the enzyme activity, the latter denatured the enzyme completely. A pre-incubation of the cell membranes (ghosts) with ribonuclease resulted in an increase in the proteolytic activity of this fraction by some 30%.

     
  7. (7)

    It is postulated on the basis of the above findings that the main function of the proteolytic enzymes present in the cells consists in the degradation of the cell proteins.

     

Keywords

Proteolytic Activity Bacillus Cereus Osmotic Shock Bacillus Megaterium Total Enzyme 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Локализация протеаз в клетке Escherichia coli и Bacillus megaterium

Abstract

  1. (1)

    Изучалася локализация протеаз в клетках Bacillus megaterium и Escherichia coli. B. megaterium—это типичный протеолитический микроорганизм, тогда как E. coli вообще не выделяет протеазы в среду.

     
  2. (2)

    В обоих случаях около 30% общей энзиматической активности выделялось в среду при образовании протопластов или же сферопластов. Повидимомы, часть выделяемой протеазы происходит из разрушенных протопластов.

     
  3. (3)

    Фермент, встречаюшийся внутри протопластов, в обоих видах бактерий был распределен приблизительно равномерно между фракцией, осаждающейся при 10.000 x g и супернатантом. В случае E. coli доля фермента, найденного во фракции ghosts, составляет 45%, для B. megaterium −38%.

     
  4. (4)

    Для сферопластов E. coli было произведено подробное исследование распределения фермента. В рибосомальной фракции, осаждающейся при 105 000 x g, было найдено около 10% от общего количества фермента; в цитоплазме было обнаружено около 60% протеазы, во фракции цитоплазматической оболочки −30%. Повышение доли фермента, найденного в цитоплазме, вызывалось солубилизацией протеазы из фркации ghosts при промывании буферным раствором.

     
  5. (5)

    Путем воздействия этилендиаминотетрауксусной кислотой или мочевиной на рибосомы не удавалось повысить протеолитическую активность. EDTA понижала энзиматическую активность, мочевина пояностью денатурировала фермент. Предварительная инкубация клеточных оболочек (ghosts) с рибонуклеазой велак повышению протеолитической активности этой фракции приблизительно на 30%.

     
  6. (6)

    На основе вышеприведенных фактов высказывается предположение, что главной функцией протеолитических энзимов, присутствующих в клетках, является, по-видимомы, катализ деградации клеточных белков.

     

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Copyright information

© Nakladatelství Československé akademie věd 1961

Authors and Affiliations

  • J. Chaloupka
    • 1
  1. 1.Department of Microbiology, Institute of BiologyCzechoslovak Academy of SciencesPrague 6

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