Intestinal dipeptidases I. Spectrophotometric determination and characterization of dipeptidase activity in pig intestinal mucosa

Josefsson, Lars; Lindberg, Tor

doi:10.1016/s0926-6593(65)80183-7

Cited by 104 publications

(30 citation statements)

References 14 publications

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“…Hydrolyzing activity of L-ala-L-pro, L-leu-Lpro, L-pro-L-pro, L-pro-gly and L-pro-L-leu were measured by the same method. Hydrolysis of gly-hydroxy-L-pro and gly-gly was measured by the method of Josefsson and Lindberg (15). The product of hydrolysis of gly-gly-gly was measured by amino acid analyzer.…”

Section: Methodsmentioning

confidence: 99%

Human Erythrocyte Prolidase and Prolidase Deficiency

et al. 1982

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SummaryCase. A female patient with prolidase deficiency was examined.Biochemical studies on human prolidase (EC 3.4.13.9) and prolidase deficiency are described. The urine sample from a 32-year-old female with prolidase deficiency was examined. Diagnosis was based on clinical features and defects of prolidase in her erythrocytes. She excreted massive amounts of iminopeptides, where three major peptides were identified; aspartyl-proline, glutamyl-proline and glycyl-proline. The prolidase was purified a p proximately 10,000-fold from the normal human erythrocytes through an eight step procedure. The purified enzyme consisted of two identical subunits of which the molecular weight was calculated to be 55.000. The relative cleavage rates of the enzvme for, and glycyl-hydroxy-L-proline were 100%, 53%, 27%, 31% and 2%. respectively. he relative substrate specificity of the enzyme offers a reasonable explanation for the presence of a higher level of urinary imidodipeptides in a patient with prolidase deficiency. An attempt at erythrocyte transfusion was performed, aimed at enzyme replacement therapy. After the transfusion (erythrocytes from 800 ml of whole blood), the prolidase activity of the peripheral erythrocyte was elevated to approximately 35% of the normal values and gradually decresed (half-life, 41 days). During this period urinary peptide-bound proline was monitored, but no significant change was observed. SpeculationThe prolidase activity of transfused erythrocytes is relatively stable; however, intracellular enzyme activity has no effect on net proline loss and skin lesions. Enzyme replacement may be a possible attempt at therapy of the disease, but other forms of replacement should be tried.Prolidase deficiency is a rare genetic disease inherited by an autosomal recessive trait and associated with chronic ulcerative dermatitis, mental retardation and massive urinary excretion of imidodipeptides (22). Since the first case was described by Powell et al. in 1974 (21), additional cases have been reported (3,9, 11,13,20,23). Probable cases of prolidase deficiency suspected by urinary excreted imidodipeptides and characteristic clinical features were reported (5,10,14,17). The disease can be diagnosed by the assay of prolidase activity in erythrocyte (8, 13, 21, 23, 26), leukocyte (21, 20, 26) and cultured skin fibroblasts (23). Some of the properties of human prolidase derived from human erythrocytes was studied by Adams et al. (1). Substrate specificity of purified human prolidase has not been investigated so far. It is known, however, that substrate specificity of prolidase obtained from several animal species is not uniform (2,7,24). In the present report, we describe the biochemical characterization of human erythrocyte prolidase, identification of urinary excreted peptides with a female case of prolidase deficiency and the effect of erythrocyte transfusion on urinary excreted iminopeptides.Although a detaiied clinical bbsewation will bk reported elsewhere, especially on the skin lesions, the case is brie...

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Section: Methodsmentioning

confidence: 99%

Human Erythrocyte Prolidase and Prolidase Deficiency

et al. 1982

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“…For the assay of peptide hydrolase activity after column chromatographic fractionation (see below), the method of Josefsson and Lindberg (22) was used. The standard assay mixture, containing 0.1 ml of peptide substrate (30 and mixed quickly with a Teflon stirrer.…”

Section: Methodsmentioning

confidence: 99%

Peptide hydrolases in the brush border and soluble fractions of small intestinal mucosa of rat and man

Kim¹,

Birtwhistle²,

Kim³

1972

J. Clin. Invest.

160

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A BST RA CT Peptide hydrolases, catalyzing the hydrolysis of 13 dipeptides and 5 tripeptides into their respective amino acids, were studied in small intestinal mucosa and other tissues, in man and in the rat.Studies on the subcellular distribution of these enzymes showed enzyme activities in both the soluble and brush border fractions of the rat small intestinal mucosa, the former constituting 80-90% and the latter 10-15% of the total activity. Zymogram studies of peptide hydrolases, in both fractions, yielded multiple bands indicating multiple zones of enzyme activity. With most substrates a rather broad range of enzyme activities was observed in the soluble fraction differing only slightly from substrate to substrate, the exception being when L-leucyl-L-proline was used: this latter led to a zymogram pattern which was quite distinct. The synthetic substrates, L-leucyl-P-naphthylamide and Lleucinamide appeared to be hydrolyzed by two electrophoretically distinct enzymes, different from those hydrolyzing other leucyl-containing peptide substrates.Zymogram patterns of the brush border membrane fraction were quite different from those of the soluble fraction of rat small intestine indicating that enzymes from the two sources may be different. No comparable human data were obtained.Peptide hydrolases in the soluble fractions of various organs from the same species gave similar zymogram patterns, while those from the plasma membrane-bound fractions of different organs in the same species were peculiar to each organ. From these data, it is suggested that peptide hydrolases in the brush border and the soluble fractions of small intestine are distinct enzymes and may play different roles in cellular function.

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“…For this investigation, two new techniques were developed; one is a method that permits rapid screening of tissue extracts for hydrolase activity by use of high-voltage paper electrophoresis, the other is a method for quantitation of hydrolysis of dipeptides containing L-phenylalanine, L-tyrosine, or L-tryptophan. The application of these and other (7) methods to the study of intestinal biopsy specimens from human subjects revealed a deficiency of imidopeptide hydrolase (prolidase) activity' in three patients with subtotal villus atrophy.…”

Section: Introductionmentioning

confidence: 99%

Peptide hydrolase activities of the mucosa of human small intestine

Heizer¹,

Laster²

1969

J. Clin. Invest.

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A B S T R A C T Few studies have been published on peptide hydrolase activities of human small intestine mucosa. We developed methods to screen tissue extracts for such enzymes and to quantitate hydrolase activities for dipeptides containing the aromatic amino acid L-phenylalanine. The screening procedure indicated glyCyl-L-proline hydrolase activity was reduced in biopsy specimens from patients with flattened intestinal mucosa. To explore this further, we established optimal assay conditions for hydrolaseBiopsy specimens from patients with various intestinal disorders, but without flattened mucosa, and from three patients with flattened mucosa, showed a disproportionate reduction in activities (a) and (b), with the reduction being significantly more marked in the latter patients. We suggest that intestinal imidopeptide hydrolase activities, such as (a) and (b), are sensitive to changes in intestinal disease generally, particularly to the altered physiology associated with flattening of the mucosa, and are secondary to, rather than a cause of, the intestinal pathology.Our finding that intestinal alkaline phosphatase activity tended to parallel imidopeptide hydrolase activity, and that activity (a) was partially localized to the particulate fraction of mucosal homogenate, suggested that imidopeptide hydrolase activities may be located in the microvilli of the intestinal epithelium and that, like alkaline phosphatase activity, they may be reduced in flattened mucosae, in part at least because of the pathologic changes in the microvilli.Dr. Heizer's present address is

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Intestinal dipeptidases I. Spectrophotometric determination and characterization of dipeptidase activity in pig intestinal mucosa

Cited by 104 publications

References 14 publications

Human Erythrocyte Prolidase and Prolidase Deficiency

Human Erythrocyte Prolidase and Prolidase Deficiency

Peptide hydrolases in the brush border and soluble fractions of small intestinal mucosa of rat and man

Peptide hydrolase activities of the mucosa of human small intestine

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