Enhancement of brush border membrane peptidase activity in rat jejunum induced by starvation

2000 ◽  
Vol 440 (1) ◽  
pp. 75 ◽  
Author(s):  
Takashi Ihara ◽  
Tomoyuki Tsujikawa ◽  
Yoshihide Fujiyama ◽  
Hisao Ueyama ◽  
Iwao Ohkubo ◽  
...  
Keyword(s):  
Brush Border ◽  
Brush Border Membrane ◽  
Peptidase Activity ◽  
Rat Jejunum

Enhancement of brush border membrane peptidase activity in rat jejunum induced by starvation

2000 ◽  
Vol 440 (1) ◽  
pp. 75-83 ◽  
Author(s):  
Takashi Ihara ◽  
Tomoyuki Tsujikawa ◽  
Yoshihide Fujiyama ◽  
Hisao Ueyama ◽  
Iwao Ohkubo ◽  
...  
Keyword(s):  
Brush Border ◽  
Brush Border Membrane ◽  
Peptidase Activity ◽  
Rat Jejunum

Subcellular Distribution of Hydrolase Activities for Glycine and Leucine Homopeptides in Human Jejunum

1978 ◽  
Vol 54 (2) ◽  
pp. 205-207
Author(s):  
J. A. Nicholson ◽  
T. J. Peters
Keyword(s):  
Brush Border ◽  
Subcellular Distribution ◽  
Brush Border Membrane ◽  
Specific Marker ◽  
Peptidase Activity ◽  
Small Peptides ◽  
Normal Human ◽  
Analytical Fractionation ◽  
Hydrolysis Of ◽  
Isopycnic Centrifugation

1. The subcellular distribution of peptidase activities in the normal human jejunum against glycine and leucine homopeptides has been investigated with an analytical fractionation technique. 2. An 8000 g-min supernatant was prepared from homogenates of Crosby capsule biopsy specimens and subjected to isopycnic centrifugation in a Beaufay automatic zonal rotor. 3. The distribution of subcellular organelles in the gradient was established by measurement of organelle-specific marker enzymes. 4. A sensitive fluorimetric assay for glycine peptidase was developed and used for the localization of peptidase activity with peptides composed of from two to five glycine residues as substrates. 5. Glycine peptidase activity was located in the cytosol and in the brush-border membrane but the distribution of activity varied markedly with the chain-length of substrate; the longer the peptide the greater the proportion of activity associated with the brush border. Leucine peptidase showed a similar variation in cytosol—brush border distributions. 6. The results are consistent with concepts that suggest absorption and intracellular hydrolysis of small peptides and brush-border digestion of larger peptides.

Transport of Methionine Hydroxy Analog across the Brush Border Membrane of Rat Jejunum

1987 ◽  
Vol 117 (7) ◽  
pp. 1241-1246 ◽  
Author(s):  
Patrick Brachet ◽  
Antoine Puigserver
Keyword(s):  
Brush Border ◽  
Brush Border Membrane ◽  
Rat Jejunum

Ontogenesis of intestinal taurine transport: evidence for a beta-carrier in developing rat jejunum

1988 ◽  
Vol 254 (6) ◽  
pp. G870-G877 ◽  
Author(s):  
M. S. Moyer ◽  
A. L. Goodrich ◽  
M. M. Rolfes ◽  
F. J. Suchy
Keyword(s):  
Amino Acids ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Equilibrium Concentration ◽  
Membrane Vesicles ◽  
Transport Systems ◽  
Rat Jejunum ◽  
Adult Rats ◽  
Taurine Transport ◽  
Taurine Uptake

Taurine, a sulfur-containing beta-amino acid, may be conditionally essential during development. However, the existence of a carrier system for beta-amino acids has not been demonstrated in brush-border membrane vesicles (BBMV) from adult rat jejunum. We studied the uptake of [3H]taurine in BBMV prepared from the jejunum of developing and adult rats using a cation-precipitation technique. Uptake of 10 microM [3H]taurine by adult BBMV was slightly enhanced in the presence of an inwardly directed 100 mM Na+ gradient compared with a K+ gradient, and there was no intravesicular accumulation of isotope above the equilibrium concentration ("overshoot"). In contrast, taurine transport by BBMV from 10-day-old rat pups was markedly accelerated in the presence of a Na+ gradient compared with a K+ gradient and a twofold overshoot was observed. Na+-dependent taurine uptake was inhibited by the structural analogues hypotaurine and beta-alanine but not by alpha-alanine or glutamine, which are amino acids served by other transport systems. By computer analysis, Na+-dependent taurine uptake (2-1,000 microM) was saturable with an apparent Km of 74.80 +/- 11.87 microM and a Vmax of 53.55 +/- 2.76 pmol.mg protein-1.min-1. With increasing postnatal age, there was a marked decrease in the initial rate and peak intravesicular accumulation of taurine with disappearance of the overshoot by 21 days of age. We conclude 1) a Na+-dependent carrier mechanism for taurine transport is present in the brush-border membrane of suckling rat jejunum and 2) the activity of this carrier decreases after weaning.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of ethanol on peptidases of hamster jejunal brush-border membrane

1982 ◽  
Vol 242 (5) ◽  
pp. G442-G447
Author(s):  
P. K. Dinda ◽  
I. T. Beck
Keyword(s):  
Conformational Changes ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Kinetic Studies ◽  
Inhibitory Effect ◽  
Time Dependent ◽  
Peptidase Activity ◽  
Dependent Manner ◽  
Dose Dependent ◽  
Hydrolysis Of

This study was undertaken to investigate the effect of ethanol on the brush-border activity of the small intestine. Brush-border membrane isolated from hamster jejunum was incubated with L-phenylalanylglycine (Phe-Gly), L-leucylglycine (Leu-Gly), or glycyl-L-tyrosine (Gly-Tyr) in the absence and presence of 1-5% (wt/vol) ethanol, and the L-amino acids liberated were determined. Ethanol was found to depress the hydrolysis of all peptides in a dose-dependent manner. The inhibitory effect of ethanol on the peptidases does not appear to be time dependent. The ethanol-induced inhibition of peptidase activity is completely reversible. Kinetic studies indicate that ethanol caused a decrease in the Vmax of the enzymes responsible for the hydrolysis of the Phe-Gly and Gly-Tyr but did not have any effect on their Km. In the hydrolysis of Leu-Gly, two enzymes were involved, and ethanol depressed the Vmax of both without affecting the Km of either. These findings suggest that ethanol produces conformational changes of the peptidases involved in the hydrolysis of these three dipeptides.

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