Extracellular acid phosphatase as a minor enzyme during the production of proteinases byHumicola lutea 120-5

Lysosome-disrupting enzyme substrates have been used to distinguish between lysosomal and prelysosomal compartments along the endocytic pathway in isolated rat hepatocytes. The cells were incubated for various periods of time with 125I-labelled tyramine cellobiose (125I-TC) covalently coupled to asialoorosomucoid (AOM) (125I-TC-AOM); this molecule is internalized by receptor-mediated endocytosis and degraded in lysosomes, where the degradation products (acid-soluble, radio-labelled short peptides) accumulate, Glycyl-L-phenylalanine 2-naphthylamide (GPN) and methionine O-methyl ester (MOM), which are hydrolysed by lysosomal cathepsin C and a lysosomal esterase respectively, both diffused into hepatocytic lysosomes after electrodisruption of the cells. Intralysosomal accumulation of the hydrolysis products (amino acids) of these substrates caused osmotic lysis of more than 90% of the lysosomes, as measured by the release of acid-soluble radioactivity derived from 125I-TC-AOM degradation. The acid-soluble radioactivity coincided in sucrose-density gradients with a major peak of the lysosomal marker enzyme acid phosphatase at 1.18 g/ml; in addition a minor, presumably endosomal, acid phosphatase peak was observed around 1.14 g/ml. The major peak of acid phosphatase was almost completely released by GPN (and by MOM), while the minor peak seemed unaffected by GPN. Acid-insoluble radioactivity, presumably in endosomes, banded (after 1 h of 125I-TC-AOM uptake) as a major peak at 1.14 and a minor peak at 1.18 g/ml in sucrose gradients, and was not significantly released by GPN. GPN thus appears to be an excellent tool by which to distinguish between endosomes and lysosomes. MOM, on the other hand, released some radioactivity and acid phosphatase from endosomes as well as from lysosomes.

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Chromatographic separation, of extracellular acid phosphatase of tobacco cells cultured under Pi-supplied and omitted conditions

Plant and Cell Physiology ◽

10.1093/oxfordjournals.pcp.a075449 ◽

1977 ◽

Vol 18 (2) ◽

pp. 413-420 ◽

Cited By ~ 14

Author(s):

Yaéko Ninomiya ◽

Katsuji Ueki ◽

Sitiro Sato

Keyword(s):

Acid Phosphatase ◽

Chromatographic Separation ◽

Tobacco Cells ◽

Extracellular Acid Phosphatase ◽

Cells Cultured

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Croatian produced unifloral honey characterized according to the protein and proline content and enzyme activities

Journal of Apicultural Science ◽

10.1515/jas-2016-0005 ◽

2016 ◽

Vol 60 (1) ◽

pp. 39-48 ◽

Cited By ~ 7

Author(s):

Ivana Flanjak ◽

Ivica Strelec ◽

Daniela Kenjerić ◽

Ljiljana Primorac

Keyword(s):

Enzyme Activity ◽

Acid Phosphatase ◽

Protein Content ◽

Glucose Oxidase ◽

Phosphatase Activity ◽

Enzyme Activities ◽

Acid Phosphatase Activity ◽

Black Locust ◽

Proline Content ◽

A Minor

Abstract In honey, the content of proteins, including the enzymes, is relatively low and has a minor nutritive significance. On the other hand, the proteins, including the enzymes, are usually used as honey quality evaluation parameters. This is because protein content and enzyme activities vary regarding the botanical origin of the honey. Since the results of protein content, glucose-oxidase, and acid phosphatase, for honeys produced in Croatia, are not available, four of the most abundant honey types produced in Croatia (black locust, sage, chestnut, and honeydew honey) are characterised according to the protein and proline content and enzyme activities. The characterisation was done to determine specificities and contribute to the characterisation of unifloral honeys. Dark honey types (honeydew and chestnut honey) had a higher proline content, and diastase, invertase, and glucose-oxidase activity than lighter sage and black locust honey. Black locust honey has a naturally low enzyme activity and showed the highest acid phosphatase activity among the analysed honey types, while honeydew honey, otherwise known to possess high proline content and enzyme activity, had a low protein content comparable to black locust honey. Statistically significant correlations were obtained between all analysed parameters, with the exception of acid phosphatase activity.

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Identification and partial characterization of an extracellular acid phosphatase activity of Leishmania donovani promastigotes

Molecular and Cellular Biology ◽

10.1128/mcb.2.1.76-81.1982 ◽

1982 ◽

Vol 2 (1) ◽

pp. 76-81

Author(s):

M Gottlieb ◽

D M Dwyer

Keyword(s):

Acid Phosphatase ◽

Leishmania Donovani ◽

Surface Membrane ◽

Extracellular Enzyme ◽

Growth Cycle ◽

Growth Media ◽

Ph Optimum ◽

Membrane Bound ◽

Extracellular Acid Phosphatase

An extracellular acid phosphatase was detected in the growth media of Leishmania donovani promastigotes. The enzyme was released at all stages of the growth cycle and in amounts which accounted for 90% of the total amount of this enzyme in the culture. The exoenzyme exhibited a pH optimum of 4.5 to 5.0 and was active with a variety of organic phosphates. The enzymatic activity was excluded from Sephacryl S-300 and was retained by ultrafilters with nominal molecular weight cutoffs of up to 300,000. The results of comparative studies indicated that the extracellular enzyme was distinct from a surface membrane-bound acid phosphatase of L. donovani promastigotes which has been previously described.

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