Studies on enzymatic histochemistry. XXIV. Localization of peptidase in the ameba

Endocytic Processes

“…The association of acid phosphatase, acid protease and amylase with formed cytoplasmic organelles of amoebae centrifuged in vivo was shown by Holter and co-workers (Holter and Doyle, 1938;Holter and Lovtrup, 1949;Holter and Lowy, 1959). The association of acid phosphatase, acid protease and amylase with formed cytoplasmic organelles of amoebae centrifuged in vivo was shown by Holter and co-workers (Holter and Doyle, 1938;Holter and Lovtrup, 1949;Holter and Lowy, 1959).…”

“…Studies on enzyme levels on starved nucleate and auncleate amoe bae (Holter and Kopac, 1937;Urbani, 1952a;Brachet, 1954) indicated that while dipeptidase activities remained constant during 14 days of starvation, decreases in esterase and acid phosphatase activities were more pronounced in anucleate than in nucleate halves. Studies on enzyme levels on starved nucleate and auncleate amoe bae (Holter and Kopac, 1937;Urbani, 1952a;Brachet, 1954) indicated that while dipeptidase activities remained constant during 14 days of starvation, decreases in esterase and acid phosphatase activities were more pronounced in anucleate than in nucleate halves.…”

“…Rothschild (1966Rothschild ( , 1967, in studies on the distribution of enzymes in C. carolinensis by density gradient centrifugation of homogenates, found one acid phosphomonoesterase together with acid protease to be particle-associated. Several studies on dipeptidase (optimum pH 7.4) indicated that its distribution was cytoplasmic rather than particle-bound, hence by these criteria not a lysosomal enzyme (Holter and Kopac, 1937;Holter and Lovtrup, 1949). Several studies on dipeptidase (optimum pH 7.4) indicated that its distribution was cytoplasmic rather than particle-bound, hence by these criteria not a lysosomal enzyme (Holter and Kopac, 1937;Holter and Lovtrup, 1949).…”

Principles of Enzymic Histo‐ and Cytochemistry

“…The micromanipulator and its use for this purpose have been described in reviews by Chambers and Kopac (28), and by Kopac and others in the volume edited by Reyniers (134). It is often of value to combine the centrifugal technique with microdissection to obtain material for enzyme investigations, e.g., the studies of peptidase in parts of the amoeba (83).…”

Protein Synthesis in Plants

“…Linderstram-Lang & Holter (1934) centrifuged eggs of Psammechinus and found the greater part of the dipeptidase activity to be resident in the heavier layer containing the mitochondria, although other granular components of the cytoplasm were also present. I n other marine ova and in Amoeba, however, the peptidase was found to be diffusely distributed in the hyaline plasm or matrix of the cytoplasm (Holter, 1936;Holter & Kopac, 1937). Joyet-Lavergne (for references see Petrie & Williams, 1938, p. 354), on the basis of a reaction with oxidation-reduction indicators, believes that mitochondria are also the seat of respiration, which would be of interest since the sequence of protein synthesis is coupled with respiration at least at one point (cf.…”