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

Kim, Y. S.; Birtwhistle, W.; Kim, Y. W.

doi:10.1172/jci106938

Cited by 160 publications

(108 citation statements)

References 40 publications

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“…When (Zubstov and Podorozhnaya, 1979), and that gastric pepsins are sensitive to any dietary changes ; the activity of these enzymes increases in the rat when dietary protein intake augments (Snook and Meyer, 1964) or varies in the dog with the type of protein (Storozuk, 1968 Some studies seem to indicate that the digestive enzymes adapt principally to the amount of nitrogenous material ingested. This idea, which appears again in the present paper, was evidenced in the studies of Behrman and Kare (1969) in the dog, Hulan and Bird (1972) (Kim, Birtwhistle and Kim, 1972 ;Heizer, Kerley and lsselbacher, 1972). One of the first effects that diet has on the development of these enzymes is seen during fasting which causes brush border activities in the rat to decrease while the cytoplasmic activities increase (Kim et al, 1973) ; this would imply that the former enzymes are adaptive.…”

supporting

confidence: 78%

The adaptation of digestive enzymes to the diet : Its physiological significance

Corring¹

1980

Reprod. Nutr. Dévelop.

125

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supporting

confidence: 78%

The adaptation of digestive enzymes to the diet : Its physiological significance

Corring¹

1980

Reprod. Nutr. Dévelop.

125

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“…The non-sedimentable fraction (cytosol) showed enrichment in enzymes hydrolysing Arg, Ser, and Pro. The tissue fractionation results, in general, point to the particulate heterogeneity of aminopeptidases in chicken intestine which closely resembles that observed in human and rat brain 23,24 , human placenta 25 , and developing rat cerebellum 26 . The heterogeneity of aminopeptidases is also apparent in terms of their interaction with ion exchange resins ( Figs.…”

Section: Resultssupporting

confidence: 62%

“…Similar localization of aminopeptidase activities in sedimentable membrane fractions has also been reported in murine 20 and human 21 tissues. Among the membrane bound organelles, the nuclear fraction showed 15-33% activity which could be attributed to nuclear aminopeptidases 22 although some contribution by unbroken cells and brush borders 23 cannot be ruled out. The microsomal fraction possessed 16-33% activity against all the amino acid naphthylamide substrates, except Asp β-naphthylamide (∼ 10.4%).…”

Section: Resultsmentioning

confidence: 88%

Untitled

Damle¹,

Harikumar²,

Jamdar³

2010

ScienceAsia

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The suitability of chicken intestine, a poultry processing by-product, as a source of aminopeptidases has been evaluated. To investigate the heterogeneity of the aminopeptidases in the tissue, tissue fractions separated by differential centrifugation and ion exchange chromatography were screened for aminopeptidase activity using twelve different amino acid naphthylamide substrates. The sedimentable fractions obtained by differential centrifugation, although differing in substrate profile, were largely enriched (72-90%) in aminopeptidase activities. However, the enzymes hydrolysing pro-β-naphthylamide largely belonged to the soluble fraction (> 40%). On the basis of their interaction with the ion exchange resins, DEAE and CM Sepharose, six regions of aminopeptidase activity differing in their elution profiles and substrate specificities were identified. Data reveal the presence of a number of aminopeptidases with multiple specificities in chicken intestine which could be used for industrial applications.

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“…Normal mucosal scrapings and minced tumors were weighed and homogenized in 4 volumes (w/v) of cold 0.16 M NaCl-0.01 M cacodylate acetate buffer (pH 7.0) using a Polytron homogenizer and passed through two layers of cheesecloth. The membrane fraction containing plasma, nuclear, mitochondrial, and microsomal membranes was then centrifuged at 120,000 X g for 60 min (21,22). Examination of the pellet by phase microscopy revealed the presence of membranes without contamination by cell debris.…”

mentioning

confidence: 99%

Alterations of Membrane Glycopeptides in Human Colonic Adenocarcinoma

Kim

Isaacs

Perdomo

1974

Proc. Natl. Acad. Sci. U.S.A.

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Membrane glycopeptides were examined in human colonic adenocarcinoma and normal colonic mucosa. The carbohydrates of membrane glycopeptides were found to be markedly reduced in tumor tissue and the relative proportions of the various sugars were altered. Although all of the sugars were lower in tumor tissue when compared to the adjacent normal mucosa, galactosamine, fucose, and sialic acid were more significantly reduced. Examination of the blood group activity and lectin-binding properties of membrane glycopeptides revealed that specific carbohydrate structures had changed in the tumor tissue. Most striking of these changes was the disappearance of glycoprotein-associated blood group A activity. Assay of the enzyme responsible for synthesis of the blood group A determinant showed that this glycosyltransferase activity was greatly diminished in tumor tissue. A galactosyltransferase and a fucosyltransferase were also significantly lower in the tumor tissue whereas the levels of another galactosyltransferase and a sialyltransferase were unaltered. Glycosidase activities in the normal and tumor tissues were similar. The results show that an alteration in glycoprotein biosynthesis occurred during tumorigenesis that resulted in a modified membrane glycoprotein composition and that these changes are probably a reflection of reduced levels of the enzymes responsible for glycoprotein synthesis.Glycoproteins and glycolipids are ubiquitous in mammalian cells and are major components of cellular membranes (1-6). Glycopeptides isolated from the plasma membranes of cells such as erythrocytes and fibroblasts have diverse immunological properties, among them blood group and virus agglutinating activities (3,4). It has been shown that these properties are determined by the terminal sequence and linkage of sugars in glycoprotein and glycolipid structures. The surface membranes and the microsomal membranes of intestinal epithelial cells also contain various carbohydrate moieties (2,7,8).Phenomena characteristic of tumor growth such as alteration of cell-cell interactions and disturbance of normal immunological processes strongly implicate cellular membranes in the process of tumorous transformation. Differences in composition of membrane glycoproteins resulting from viral transformation of cells and in the metabolic systems which elaborate and degrade them have been reported (9-17). Although a consensus has not been reached, the studies uniAbbreviations: con A, concanavalin A; a1AGP-NANA, a,-acid glycoprotein minus sialic acid; OSM-NANA. ovine submaxillary mucin minus sialic acid; ac-AGP-NANA-GAL, a-acid glycoprotein minus sialic acid, minus galactose; NANA, N-acetylneuraminic acid.formly suggest that both quantitative and qualitative differences are induced in the membrane glycoproteins of cells after transformation. These changes apparently occur in both internally and externally located membranes (14,15). The majority of studies were performed on cultured cell systems in which the effects of various tumorigenic agents ...

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

Cited by 160 publications

References 40 publications

The adaptation of digestive enzymes to the diet : Its physiological significance

The adaptation of digestive enzymes to the diet : Its physiological significance

Untitled

Alterations of Membrane Glycopeptides in Human Colonic Adenocarcinoma

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