scholarly journals Characterization of lysosomes and lysosomal enzymes from Chediak-Higashi-syndrome cultured fibroblasts

1986 ◽  
Vol 238 (2) ◽  
pp. 589-595 ◽  
Author(s):  
A L Miller ◽  
R Stein ◽  
M Sundsmo ◽  
R Y Yeh
Keyword(s):  
Lysosomal Enzymes ◽  
Specific Activity ◽  
Skin Fibroblasts ◽  
Cultured Fibroblasts ◽  
Cultured Skin ◽  
Lysosomal Dysfunction ◽  
Chediak Higashi Syndrome ◽  
Normal Controls

Chediak-Higashi-syndrome cultured skin fibroblasts were used to study the possible involvement of lysosomal enzymes and lysosomal dysfunction in this disorder. Our evidence indicated that Chediak-Higashi fibroblasts displayed a significant decrease in the specific activity of the acidic alpha-D-mannosidase (pH 4.2) compared with normal controls. Additional studies revealed a small, but significant, decrease in the rate of degradation of 125I-labelled beta-D-glucosidase that had been endocytosed into Chediak-Higashi cells.

METACHROMASIA AND ASSAY FOR LYSOSOMAL ENZYMES IN SKIN FIBROBLASTS CULTURED FROM PATIENTS WITH CYSTIC FIBROSIS AND CONTROLS

PEDIATRICS ◽  
1971 ◽  
Vol 47 (6) ◽  
pp. 1010-1018
Author(s):  
Ilana Kraus ◽  
Irena Antonowicz ◽  
Harnish Shah ◽  
Herbert Lazarus ◽  
Harry Shwachman
Keyword(s):  
Cystic Fibrosis ◽  
Lysosomal Enzymes ◽  
Skin Fibroblasts ◽  
Control Group ◽  
Staining Reaction ◽  
Cultured Fibroblasts ◽  
Cultured Skin ◽  
Cell Strains ◽  
Absolute Correlation ◽  
Metachromatic Granules

The ability of Toluidine blue 0 to stain certain cytoplasmic elements metachromatically in cultured skin fibroblasts derived from patients with cystic fibrosis (CF) has been investigated. Fifteen of 18 (83.3%) cell strains from patients with cystic fibrosis were positive, two (11.1%) borderline, and one negative (5.5%). In a control group, 8 of 18 (44.4%) were positive, three borderline (16.6%), and seven negative (38.8%). In addition to the lack of an absolute correlation between metachromasia and CF, inconsistencies in staining reaction were continually noted. Several parameters which account for these variations have been examined. Since metachromatic granules are felt to represent lysosomal structures, a study of four lysosomal enzymes in the skin cultured fibroblasts was carried out in material from 10 patients with CF and 11 controls. No differences were noted in the activity of β-galactosidase, β-glucuronidase, aryl sulfatase, and acid phosphatase. While these studies do not support the possibility that CF is due to a lysosomal hydrolase deficiency in the metabolism of mucopolysaccharides, they do not exclude it either.

Biochemical Discrimination of Hurler and Scheie Syndromes

1979 ◽  
Vol 57 (3) ◽  
pp. 265-272 ◽  
Author(s):  
J. J. Hopwood ◽  
Vivienne Muller
Keyword(s):  
Thermal Stability ◽  
Skin Fibroblasts ◽  
Ph Optimum ◽  
Biochemical Evidence ◽  
Cultured Skin ◽  
Thermal Stability Of ◽  
Normal Controls

1. Homogenates of cultured skin fibroblasts derived from patients with α-l-iduronidase-deficiency disorders (Hurler and Scheie syndromes) were capable of hydrolysing iduronosyl anhydro-[l-3H]mannitol 6-sulphate although at considerably reduced rates compared with normal controls. 2. The Vmax. values of α-l-iduronidase from patients with Hurler or Scheie syndromes and from normal controls were 11, 12 and 833 pmol min−1 mg−1 of protein respectively; the corresponding apparent Km values were 656, 50 and 53 μmol/l respectively. The α-l-iduronidases from normal and Scheie fibroblast homogenates were shown to exhibit pH optima at 3·6 and 4·1 and were competitively inhibited by both chloride and sulphate ions: Hurler α-l-iduronidase activity exhibited one pH optimum at 3·8 and was also inhibited by chloride and to a lesser extent by sulphate ions. 3. The thermal stability of Hurler, Scheie and normal α-l-iduronidase activities at 55°C gave half-lives of approximately 1·0, 2·5 and 1·0 h respectively. 4. These biochemical findings clearly demonstrate enzyme differences for these two clinically distinct phenotypes and provide biochemical evidence that the Hurler and Scheie syndromes result from different allelic mutations.

scholarly journals Substrate-specificities of acid and alkaline ceramidases in fibroblasts from patients with Farber disease and controls

1982 ◽  
Vol 205 (2) ◽  
pp. 419-425 ◽  
Author(s):  
Toru Momoi ◽  
Yoav Ben-Yoseph ◽  
Henry L. Nadler
Keyword(s):  
Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Specific Activity ◽  
Kinetic Studies ◽  
Significant Activity ◽  
Acid Ceramidase ◽  
Ph Optimum ◽  
Farber Disease ◽  
Normal Controls

The specific activity of acid ceramidase (N-acylsphingosine deacylase, EC 3.5.1.23) was measured at pH4.5 in normal fibroblasts and in fibroblasts from patients with Farber disease and obligate heterozygotes. Greater activity was found when the synthetically made ceramide substrates contained shorter-chain fatty acids or higher content of double bonds. Acid ceramidase activities towards N-lauroyl- (C12:0), N-myristoyl- (C14:0) and N-palmitoyl- (C16:0) sphingosine (C18:1) were respectively about 38, 26 and 6 times higher than the activity towards the N-stearoyl (C18:0) substrate. The activity towards N-linolenoylsphingosine (C18:3/C18:1), N-linoleoylsphingosine (C18:2/C18:1) and N-oleoylsphingosine (C18:1/C18:1) were respectively about 5, 4 and 3 times higher than the activity towards N-stearoylsphingosine (C18:0/C18:1). The activity towards N-stearoyldihydrosphingosine (C18:0/C18:0) was about 40% of that towards N-stearoylsphingosine. Fibroblast alkaline ceramidase possessed significant activity only towards ceramides of unsaturated fatty acids, with a pH optimum of about 9.0. Deficiency of acid ceramidase activity in fibroblasts from patients with Farber disease and intermediate activities in obligate heterozygotes were demonstrated with all ceramides examined except for N-hexanoylsphingosine (C6:0/C18:1), whereas alkaline ceramidase activity was unaffected. Comparative kinetic studies of acid ceramidase activity with N-lauroylsphingosine and N-oleoylsphingosine demonstrated about 5 (2–12)-fold and 7 (4–17)-fold higher Km values in fibroblasts from patients with Farber disease as compared with normal controls. N-Lauroylsphingosine, towards which acid ceramidase activity in control fibroblasts was about 10 times higher than that towards N-oleoylsphingosine, may serve as a better substrate for enzymic diagnosis of Farber disease as well as for further characterization of the catalytically defective acid ceramidase.

scholarly journals Effect of Tunicamycin on Transport of Lysosomal Enzymes in Cultured Skin Fibroblasts

1979 ◽  
Vol 101 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Kurt FIGURA ◽  
Martin REY ◽  
Roswitha PRINZ ◽  
Kurt ULLRICH ◽  
Bruno VOSS
Keyword(s):  
Lysosomal Enzymes ◽  
Skin Fibroblasts ◽  
Cultured Skin

scholarly journals Lipoamide Dehydrogenase in Friedreich's Ataxia Fibroblasts

1978 ◽  
Vol 5 (1) ◽  
pp. 115-118 ◽  
Author(s):  
S. B. Melançon ◽  
M. Potier ◽  
L. Dallaire ◽  
G. Fontaine ◽  
B. Grenier ◽  
...  
Keyword(s):  
Subcellular Distribution ◽  
Specific Activity ◽  
Friedreich’S Ataxia ◽  
Friedreich's Ataxia ◽  
Skin Fibroblasts ◽  
Lipoamide Dehydrogenase ◽  
Normal Controls

SUMMARY:Lipoamide dehydrogenase was measued in cultivated skin fibroblasts from twelve patients with Friedreich's ataxia and nine normal controls. No difference in specific activity, subcellular distribution and Vmax or Km was observed between patients and controls.

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