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ESTIMATION OF CELL LYSIS. DETERMINATION OF AMINOPEPTIDASE IN EXTRACTS OF STREPTOCOCCUS MITIS , ATCC 903
Author(s) -
Linder L.,
Lindquist L.,
Söder P.Ö.,
Holme T.
Publication year - 1974
Publication title -
acta pathologica microbiologica scandinavica section b microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0365-5563
DOI - 10.1111/j.1699-0463.1974.tb00226.x
Subject(s) - lysis , streptococcus mitis , aminopeptidase , enzyme , intracellular , enzyme assay , chromatography , chemistry , biochemistry , substrate (aquarium) , bacteria , biology , streptococcus , leucine , amino acid , ecology , genetics
A colorimetric method has been tested for the determination of aminopeptidase in crude extracts of Streptococcus mitis. This was done in order to evaluate the possibility of using this enzyme as an intracellular marker in studies concerned with the quantitation of cell lysis. No purification of the enzyme was applied since the determination of cell lysis by an intracellular enzyme marker is dependent on the accurate and rapid measurement of the enzyme activity in supernatants from autolyzing cultures. Under the assay conditions used the enzymic reaction proceeded at constant rate, proportional to enzyme concentration over a wide range. The rate of the enzymatic reaction was maximal at 35–40° C. The optimum pH for activity was 7.2. The enzyme was stable in the pH‐range 5.2–9.8. The rate of the reaction was decreased at high substrate concentration.