scholarly journals Biosynthesis of intestinal microvillar proteins. Pulse-chase labelling studies on maltase-glucoamylase, aminopeptidase A and dipeptidyl peptidase IV

1983 ◽  
Vol 210 (2) ◽  
pp. 389-393 ◽  
Author(s):  
E M Danielsen ◽  
H Sjöström ◽  
O Norén
Keyword(s):  
Organ Culture ◽  
Membrane Fraction ◽  
Bound State ◽  
Dipeptidyl Peptidase ◽  
Dipeptidyl Peptidase Iv ◽  
Soluble Form ◽  
Membrane Bound ◽  
Aminopeptidase A ◽  
High Mannose ◽  
Small Intestinal

The biogenesis of three intestinal microvillar enzymes, maltase-glucoamylase (EC 3.2.1.20), aminopeptidase A (aspartate aminopeptidase, EC 3.4.11.7) and dipeptidyl peptidase IV (EC 3.4.14.5), was studied by pulse-chase labelling of pig small-intestinal explants kept in organ culture. The earliest detectable forms of the enzymes were polypeptides of Mr 225000, 140000 and 115000 respectively. These were found to represent the enzymes in a ‘high-mannose’ state of glycosylation, as judged by their susceptibility to treatment with endo-beta-N-acetylglucosaminidase H (EC 3.2.1.96). After about 40-60 min of chase, maltase-glucoamylase, aminopeptidase A and dipeptidyl peptidase IV were further modified to yield the mature polypeptides of Mr 245000, 170000 and 137000 respectively, which were expressed at the microvillar membrane after 60-90 min of chase. The fact that the enzymes before reaching the microvillar membrane were found in a Ca2+-precipitated membrane fraction (intracellular and basolateral membranes), but not in soluble form, indicates that during biogenesis maltase-glucoamylase, aminopeptidase A and dipeptidyl peptidase IV are transported and assembled in a membrane-bound state.

scholarly journals Influence of dipeptidyl peptidase IV on enzymatic properties of adenosine deaminase.

2006 ◽  
Vol 53 (3) ◽  
pp. 539-546 ◽  
Author(s):  
Svetlana Sharoyan ◽  
Alvard Antonyan ◽  
Sona Mardanyan ◽  
Giulio Lupidi ◽  
Gloria Cristalli
Keyword(s):  
Adenosine Deaminase ◽  
Immune Cell ◽  
Dipeptidyl Peptidase ◽  
Dipeptidyl Peptidase Iv ◽  
Soluble Form ◽  
Kidney Cortex ◽  
Peptidase Activity ◽  
Extracellular Medium ◽  
Ph Profile ◽  
Enzyme Preparations

The importance of ADA (adenosine deaminase) in the immune system and the role of its interaction with an ADA-binding cell membrane protein dipeptidyl peptidase IV (DPPIV), identical to the activated immune cell antigen, CD26, has attracted the interest of researchers for many years. To investigate the specific properties in the structure-function relationship of the ADA/DPPIV-CD26 complex, its soluble form, identical to large ADA (LADA), was isolated from human blood serum, human pleural fluid and bovine kidney cortex. The kinetic constants (Km and Vmax) of LADA and of small ADA (SADA), purified from bovine lung and spleen, were compared using adenosine (Ado) and 2'-deoxyadenosine (2'-dAdo) as substrates. The Michaelis constant, Km, evidences a higher affinity of both substrates (in particular of more toxic 2'-dAdo) for LADA and proves the modulation of toxic nucleoside neutralization in the extracellular medium due to complex formation between ADA and DPPIV-CD26. The values of Vmax are significantly higher for SADA, but the efficiency, Vmax/Km, in LADA-catalyzed 2'-dAdo deamination is higher than that in Ado deamination. The interaction of all enzyme preparations with derivatives of adenosine and erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA) was studied. 1-DeazaEHNA and 3-deazaEHNA demonstrate stronger inhibiting activity towards LADA, the DPPIV-CD26-bound form of ADA. The observed differences between the properties of the two ADA isoforms may be considered as a consequence of SADA binding with DPPIV-CD26. Both SADA and LADA indicated a similar pH-profile of adenosine deamination reaction with the optimum at pHs 6.5-7.5, while the pH-profile of dipeptidyl peptidase activity of the ADA/DPPIV-CD26 complex appeared in a more alkaline region.

Characterization of a soluble form of dipeptidyl peptidase IV from pig liver

1983 ◽  
Vol 39 (9) ◽  
pp. 1005-1007 ◽  
Author(s):  
K. M. Fukasawa ◽  
K. Fukasawa ◽  
B. Y. Hiraoka ◽  
M. Harada
Keyword(s):  
Dipeptidyl Peptidase ◽  
Dipeptidyl Peptidase Iv ◽  
Soluble Form ◽  
Pig Liver

scholarly journals Immunoelectrophoretic studies on human small-intestinal brush-border proteins

1981 ◽  
Vol 193 (3) ◽  
pp. 887-890 ◽  
Author(s):  
H Skovbjerg
Keyword(s):  
Enzyme Activity ◽  
Brush Border ◽  
Dipeptidyl Peptidase ◽  
Enzyme Synthesis ◽  
Dipeptidyl Peptidase Iv ◽  
Immunoreactive Protein ◽  
Intestinal Brush Border ◽  
Small Intestinal ◽  
Brush Border Enzyme

The amounts of lactase (beta-D-galactosidase, EC 3.2.1.23), sucrase (sucrose alpha-D-glucohydrolase, EC 3.2.1.48), maltase (alpha-D-glucosidase, EC 3.2.1.20) microvillus aminopeptidase (EC 3.4.11.2) and dipeptidyl peptidase IV (EC 3.4.14.-) in tangentially sectioned biopsies from jejunum were studied by quantitative immunoelectrophoresis and enzymic assays. All enzymes had their maximum activities near the mid-region of the villi and their lowest activities at the bases of the crypts. The ratio between enzyme activity and immunoreactive protein was constant along the villus-crypt axis. This result is consistent with a continuous brush-border-enzyme synthesis as the enterocytes migrate up the villi.

Renin Release from Renin Granules in the Dog

1978 ◽  
Vol 55 (1) ◽  
pp. 11-14 ◽  
Author(s):  
S. Funakawa ◽  
T. Higashio ◽  
K. Yamamoto
Keyword(s):  
Membrane Fraction ◽  
Renin Activity ◽  
Renin Release ◽  
Soluble Form ◽  
Freezing And Thawing ◽  
External Concentration ◽  
Osmotic Lysis ◽  
Membrane Bound ◽  
Release Form ◽  
Three Components

1. Renin release from isolated dog renin granules was limited to within 20% of the total renin during incubation at 37°C in isotonic medium and did not depend on the external concentration of renin. 2. Although the renin granules were osmotically and mechanically fragile, they were quite stable at 0°C in isotonic medium. 3. The bulk of renin activity appeared in the supernatant when the granules were ruptured by osmotic lysis. About 8% of the total renin still remained in the membrane fraction of the granules after treatment by freezing and thawing. 4. Therefore stored renin in the granules can be described as comprising three components: a readily released soluble form; a soluble but hard-to-release form; a membrane-bound form.

Effect of divalent cations on the porcine kidney cortex membrane-bound form of dipeptidyl peptidase IV

2011 ◽  
Vol 43 (3) ◽  
pp. 363-371 ◽  
Author(s):  
Isel Pascual ◽  
Hansel Gómez ◽  
Tirso Pons ◽  
Mae Chappé ◽  
Miguel Angel Vargas ◽  
...  
Keyword(s):  
Divalent Cations ◽  
Dipeptidyl Peptidase ◽  
Dipeptidyl Peptidase Iv ◽  
Kidney Cortex ◽  
Porcine Kidney ◽  
Membrane Bound

Expression and localization of aminopeptidase A, aminopeptidase N, and dipeptidyl peptidase IV in benign and malignant human prostate tissue

The Prostate ◽  
1997 ◽  
Vol 33 (4) ◽  
pp. 225-232 ◽  
Author(s):  
Thomas Bogenrieder ◽  
Connie L. Finstad ◽  
Ronald H. Freeman ◽  
Christos N. Papandreou ◽  
Howard I. Scher ◽  
...  
Keyword(s):  
Dipeptidyl Peptidase ◽  
Dipeptidyl Peptidase Iv ◽  
Aminopeptidase N ◽  
Prostate Tissue ◽  
Human Prostate ◽  
Human Prostate Tissue ◽  
Aminopeptidase A
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