scholarly journals Similarities between a dipeptide hydrolase from brush-border and cytosol fractions of guinea-pig intestinal mucosa

1976 ◽  
Vol 159 (3) ◽  
pp. 715-717 ◽  
Author(s):  
C O Piggott ◽  
G O'Cuinn ◽  
P F Fottrell
Keyword(s):  
Guinea Pig ◽  
Intestinal Mucosa ◽  
Brush Border ◽  
Cytosol Fraction ◽  
Brush Border Membranes ◽  
Peptide Hydrolase

A dipeptide hydrolase from the brush border of guinea-pig intestinal mucosa was purified. The enzyme resembles another dipeptide hydrolase isolated from the cytosol fraction of intestinal mucosa. Studies on the binding of cytosol peptide hydrolase to brush-border membranes indicate that the enzyme found in the brush border may be a cytoplasmic contaminant.

scholarly journals Glucose metabolism in the mucosa of the small intestine. A study of hexokinase activity

1968 ◽  
Vol 109 (1) ◽  
pp. 35-42 ◽  
Author(s):  
L M Srivastava ◽  
P. Shakespeare ◽  
G. Hübscher
Keyword(s):  
Small Intestine ◽  
Lactate Dehydrogenase ◽  
Glucose Metabolism ◽  
Guinea Pig ◽  
Intestinal Mucosa ◽  
Brush Border ◽  
Deae Cellulose ◽  
Mitochondrial Fraction ◽  
Type Ii ◽  
Hexokinase Activity

1. The intracellular distribution of hexokinase activity was studied in the mucosa of rat and guinea-pig small intestine. In the rat 60% and in the guinea pig 45% of the hexokinase activity of homogenates were recovered in a total particulate fraction that contained only 5–17% of the homogenate activity of hexose phosphate isomerase, pyruvate kinase, lactate dehydrogenase and overall glycolysis (formation of lactate from glucose). 2. Fractionation of homogenates from guineapig small intestine showed that the particulate hexokinase activity was chiefly in the mitochondrial fraction with a small proportion in the nuclei plus brush-border fraction. 3. After chromatography of the particle-free supernatants on DEAE-cellulose, hexokinase types I and II were determined quantitatively. No evidence was obtained for the presence of hexokinase type III or glucokinase. In the preparations from guinea pigs, hexokinase types I and II amounted to 69% and 31% respectively of the eluted activity; the corresponding values for preparations from rats were 5·8% and 94·2%. 4. Total and specific hexokinase activities decreased significantly in homogenates and particle-free supernatants prepared from the intestinal mucosa of rats starved for 36hr. and increased again after re-feeding. The decrease in hexokinase activity in the particle-free supernatant from starved rats was chiefly due to a decrease in the type II enzyme.

The Hydrolysis of Glycine Oligopeptides by Guinea-Pig Intestinal Mucosa and by Isolated Brush Borders

1973 ◽  
Vol 45 (6) ◽  
pp. 803-816
Author(s):  
T. J. Peters
Keyword(s):  
Guinea Pig ◽  
Intestinal Mucosa ◽  
Brush Border ◽  
Enzyme Reaction ◽  
Intestinal Lumen ◽  
Small Intestinal Mucosa ◽  
Peptidase Activity ◽  
Reaction Products ◽  
Brush Borders ◽  
Hydrolysis Of

1. The relative rates of hydrolysis of a series of glycine homopeptides by guinea-pig small intestinal mucosa and by isolated brush borders have been studied. Oligopeptides up to and including hexaglycine were hydrolysed. No activity was detected against a series of homopolypeptides of molecular weight 10000–100000. 2. Except for activity against diglycine, the peptidase activity was greater in the brush-border fraction than in the original homogenate. The relative activity of the peptidase in the brush borders compared to the homogenate increased with increasing length oligopeptide substrate. 3. Analysis of the enzyme reaction products indicated that the brush border contained an exopeptidase. Studies with peptide derivatives containing N- and C-terminal blocking groups and with tetraglycine synthesized with either the N- or C-terminal residues labelled, demonstrated that the brush borders contained an amino-oligopeptidase. 4. Studies with inhibitors and with purified gastric and pancreatic enzymes indicated that this glycine oligopeptidase activity was not due to enzymes from the intestinal lumen which had been adsorbed to the brush borders.

scholarly journals PHOSPHATE (Pi) TRANSPORT IN RENAL BRUSH BORDER MEMBRANES (BBMV) IN NEWBORN PUPPIES (P)

1984 ◽  
Vol 18 ◽  
pp. 366A-366A
Author(s):  
Eddie S Moore ◽  
Eunice G John ◽  
Lawrence Rufr ◽  
Christine S Mooers ◽  
Nochik Park ◽  
...  
Keyword(s):  
Brush Border ◽  
Brush Border Membranes ◽  
Pi Transport ◽  
Renal Brush Border Membranes ◽  
Renal Brush Border
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