Acid Hydrolase Activity in Relation to Histological Changes in Experimental Encephalitis

1974 ◽  
Vol 2 (3) ◽  
pp. 448-450
Author(s):  
DAVID M. BOWEN ◽  
NIGEL J. BORSHELL ◽  
R. HUGH ◽  
A. FLACK ◽  
A. N. DAVISON
Keyword(s):  
Hydrolase Activity ◽  
Acid Hydrolase ◽  
Histological Changes ◽  
Experimental Encephalitis

Acid Hydrolase Activity in Osteoarthritic and Normal Human Cartilage

1973 ◽  
Vol 55 (5) ◽  
pp. 1068-1076 ◽  
Author(s):  
MICHAEL G. EHRLICH ◽  
HENRY J. MANKIN ◽  
BENJAMIN V. TREADWELL
Keyword(s):  
Hydrolase Activity ◽  
Acid Hydrolase ◽  
Human Cartilage ◽  
Normal Human

Investigation of serum acid hydrolase activity in immunodepression

1984 ◽  
Vol 97 (4) ◽  
pp. 458-460
Author(s):  
V. A. Drozhennikov ◽  
O. S. Belorusov ◽  
S. T. Tsygankova ◽  
M. M. Kapichnikov ◽  
Yu. V. Zykov ◽  
...  
Keyword(s):  
Hydrolase Activity ◽  
Acid Hydrolase

Further studies on ε-lysine acylase. The ω-N-acyl-diamino acid hydrolase activity of avian kidney

1968 ◽  
Vol 46 (5) ◽  
pp. 471-475 ◽  
Author(s):  
Jean Leclerc ◽  
Leo Benoiton
Keyword(s):  
Hydrolase Activity ◽  
Acid Hydrolase ◽  
Enzyme Preparations ◽  
Kidney Enzyme ◽  
Diamino Acid ◽  
Avian Kidney ◽  
Derivatives Of ◽  
Hog Kidney

ω-N-Acyl-diamino acids have been tested as substrates for ε-lysine acylase from animal sources. Chicken and pigeon kidney enzyme preparations hydrolyzed derivatives of lysine homologues as well as of lysine, the best substrates tested being ε-N-propionyl-lysine and ε-N-propionyl-ornithine. A modified procedure for purifying the enzyme from rat and hog kidney is presented. Some of its properties are different from those previously reported.

scholarly journals STUDIES ON LYSOSOMES

1968 ◽  
Vol 37 (2) ◽  
pp. 394-411 ◽  
Author(s):  
Günter Brittinger ◽  
Rochelle Hirschhorn ◽  
Steven D. Douglas ◽  
Gerald Weissmann
Keyword(s):  
Acid Phosphatase ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Structural Characteristics ◽  
Gradient Centrifugation ◽  
Human Lymphocytes ◽  
Peripheral Blood Lymphocytes ◽  
Hydrolase Activity ◽  
Cell Fractionation ◽  
Acid Hydrolase

Pure suspensions of human lymphocytes were separated from peripheral blood by means of nylon wool, homogenized in 0.34 M sucrose-0.01 M EDTA solution, and fractionated by differential centrifugation. The bulk of acid hydrolase activity was found to be concentrated in a 20,000 g x 20 min granular fraction, whereas nuclear, debris, and supernatant fractions contained lesser concentrations of hydrolases. Acid hydrolase activity present in the granular fraction showed appropriate "latency" as judged by its dose-dependent release into the 20,000 g x 20 min supernatant after exposure to membrane-disruptive agents such as streptolysin S, filipin, and lysolecithin. Heparin proved to be necessary in the suspending medium so that reproducible homogenization and cell fractionation could be obtained. Even excessive contamination of lymphocyte suspensions with platelets did not appreciably alter the acid hydrolase activity of lymphocyte homogenates or the distribution of enzymes in subcellular fractions. Discontinuous density-gradient centrifugation of a 500 g x 10 min supernatant, containing both acid hydrolase-rich organelles and mitochondria, resulted in partial resolution of hydrolase-rich organelles from mitochondria. Fine structural studies of the intact lymphocytes showed the presence of acid phosphatase-positive, membrane-bounded organelles. Electron microscopy of the "large granule" (20,000 g x 20 min) fraction of such lymphocytes demonstrated 80–90% mitochondria, 5–10% platelets, and 5–10% membrane-bounded acid phosphatase-positive structures. The data indicate the presence in human peripheral blood lymphocytes of acid hydrolase-rich granules which possess many of the biochemical and structural characteristics of lysosomes in other tissues.

scholarly journals Characterization of triacylglycerol hydrolase activities in isolated myocardial cells from rat heart

1985 ◽  
Vol 232 (1) ◽  
pp. 229-236 ◽  
Author(s):  
I Ramírez ◽  
A J Kryski ◽  
O Ben-Zeev ◽  
M C Schotz ◽  
D L Severson
Keyword(s):  
Ionic Strength ◽  
Subcellular Distribution ◽  
Rat Heart ◽  
High Ionic Strength ◽  
Hydrolase Activity ◽  
Affinity Column ◽  
Acid Hydrolase ◽  
Ph Optimum ◽  
Unbound Fraction ◽  
Triacylglycerol Hydrolase

Triacylglycerol (TG) hydrolase activities were characterized in myocytes isolated from rat hearts. Acid hydrolase activity with a pH optimum of 5 could be measured in myocyte homogenates, and the subcellular distribution suggested that this activity originated in lysosomes. Lipoprotein lipase (LPL) was also present in myocyte homogenates, as evidenced by TG hydrolase activity that was stimulated by serum and apolipoprotein CII, and inhibited by apolipoprotein CIII2, high ionic strength (NaCl and MgCl2, I = 1 M) and antibodies to LPL. Serum-independent neutral (pH 7.5) TG hydrolase activity was less sensitive to inhibition by 1 M-NaCl, by antibodies to LPL and by preincubation at 40 degrees C than was serum-stimulated hydrolase activity. Furthermore, there were modest but significant differences in the subcellular distribution of the serum-independent and serum-stimulated hydrolase activities. Hydrolase activities in myocyte homogenates could be solubilized by 7.2 mM-deoxycholate. Acid hydrolase activity was recovered in the unbound fraction after heparin-Sepharose chromatography, whereas LPL was bound to the affinity column and was eluted by 0.9-1.2 M-NaCl. Approximately one-third of the serum-independent TG hydrolase activity was not bound to the heparin-Sepharose affinity column. This unbound TG hydrolase activity had a pH optimum of 7 and was stimulated by 50 mM-MgCl2, but not by serum and was resistant to inhibition by high ionic strength (1 M-NaCl), to preincubation at 40 degrees C for 2 h, and by antibodies to LPL. It is concluded that, in addition to an acid lysosomal TG hydrolase and LPL, myocytes from rat heart contain a serum-independent TG hydrolase with unique characteristics.

scholarly journals Demonstration of Acid Hydrolase Activity in Primary Cultures of Bovine Brain Microvessel Endothelium

1989 ◽  
Vol 9 (3) ◽  
pp. 280-289 ◽  
Author(s):  
Anna Baranczyk-Kuzma ◽  
Thomas J. Raub ◽  
Kenneth L. Audus
Keyword(s):  
Primary Cultures ◽  
Bovine Brain ◽  
Endocytic Pathway ◽  
Hydrolase Activity ◽  
Acid Hydrolase ◽  
Acid Hydrolases ◽  
Cytochemical Localization ◽  
Brain Microvessel

The existence of lysosomes and acid hydrolase activity was demonstrated in an in vitro blood–brain barrier (BBB) model comprising primary cultures of bovine brain microvessel endothelial cell (BMEC) monolayers. BMEC lysosomes were observed by the uptake of acridine orange and fluorophore-labeled acetylated low-density lipoprotein by fluorescence microscopy. Cytochemical localization of the acid hydrolase, sulfatase, and acid phosphatase (AcP) activities with light microscopy also revealed hydrolase-positive vacuoles or lysosomes that varied in number from cell to cell. BMEC monolayers were fractionated and biochemical assays of the sulfatase, AcP, and β-galactosidase were performed. Significant activities of the acid hydrolases were found to be associated with lysosome and microsome fractions (69–77%). The majority of β-galactosidase (≈48%) and total sulfatase (≈58%) activity was associated with the lysosome fraction of the BMECs. In contrast, ≈52% of AcP activity was associated with the microsome fraction of the cells. The results of this study are consistent with the demonstration in vivo of acid hydrolases as potential factors in the endocytic pathway for transport of proteins through the BBB and as contributors to the BBB's enzymatic barrier function.

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