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Lysosomal Physiology in Tetrahymena. II. Effect of Culture Age and Temperature on the Extracellular Release of 3 Acid Hydrolases *
Author(s) -
ROTHSTEIN THOMAS L.,
BLUM J. J.
Publication year - 1974
Publication title -
the journal of protozoology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 0022-3921
DOI - 10.1111/j.1550-7408.1974.tb03632.x
Subject(s) - ribonuclease , extracellular , acid phosphatase , incubation , biochemistry , intracellular , tetrahymena , enzyme , incubation period , biology , alkaline phosphatase , arrhenius equation , chemistry , rna , activation energy , organic chemistry , gene
SYNOPSIS Tetrahymena cultures were grown from a single inoculum and collected on 3 successive days corresponding to the log, transitional, and early stationary phases of growth. Cells were washed and incubated for 5 hr in a dilute salt solution. Intra‐ and extracellular activities of acid phosphatase, α‐glucosidase, and ribonuclease were assayed, and extracellular activities corrected for proteolytic degradation. A marked increase in the cellular content of acid phosphatase and significant decreases in α‐glucosidase and ribonuclease occurred with advancing culture age. The intracellular changes in enzyme activities during incubation were roughly similar for cells of all ages. Protein content did not change appreciably during incubation. Extracellular A 255 release, monitored as an indication of the loss of RNA breakdown products, was at a minimum during incubation of transition cells. Significant quantities of all 3 acid hydrolases were released from cells of all ages except for ribonuclease from transition cells. The release of acid phosphatase and α‐glucosidase was approximately proportional to the initial cellular content of these enzymes for cells of different ages and in log cells the effect of temperature on the rates of release was described by the Arrhenius equation. Release of ribonuclease, however, was not proportional to its intracellular content nor did it vary with temperature according to the Arrhenius equation. The results suggest that acid phosphatase and α‐glucosidase are released via a first‐order process.