Intestinal surface peptide hydrolases: identification and characterization of three enzymes from rat brush border.
Peptide hydrolases were solubilized from rat small intestinal brush border by papain and separated by Sephadex G-200 chromatography, velocity gradient ultracentrifugation and polyacrylamide disc electrophoresis and designated according to approximate molecular size from sedimentation studies. Peptid...
| Main Authors: | , |
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| Format: | Journal article |
| Language: | English |
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1975
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| _version_ | 1797061443444539392 |
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| author | Wojnarowska, F Gray, G |
| author_facet | Wojnarowska, F Gray, G |
| author_sort | Wojnarowska, F |
| collection | OXFORD |
| description | Peptide hydrolases were solubilized from rat small intestinal brush border by papain and separated by Sephadex G-200 chromatography, velocity gradient ultracentrifugation and polyacrylamide disc electrophoresis and designated according to approximate molecular size from sedimentation studies. Peptidases I (apparent Mr 230 000) and II (apparent Mr 160 000) are oligopeptidases with maximum specificity for tripeptides with identical pH optima (7.5) and similar apparent Km with L-Leu-Gly (I, 0.60 MM; II, 0.76 mM). L-Leucyl-beta-naphthylamide is a competitive inhibitor of both enzymes. Concentration of peptidase II produced partial conversion to peptidase I on polyacrylamide disc electrophoresis. The third peptide hydrolase (III, Mr 120 000) is a dipeptidase with pH optimum 8.5 and apparent Km for L-Leu-Gly of 0.65 mM. These peptide hydrolases were inhibited appreciably (37-59%) by 0.2 M glycine/NaOH, Tris - HCl or Tris - glycine buffers. EDTA (5 mM) completely inhibited these enzymes but all activity was restored by dialysis against buffer without divalent ions. Subsequent addition of Mg2+, Mn2+, Co2+ or Zn2+ (1-2 mM) inhibited peptidases I and II variably (4-81%) depending upon the substrate and buffer used. In contrast peptidase III was activated slightly by metal ions (5-20%). These peptide hydrolases are strategically located at the intestinal lumen-cell interface and possess biochemical characteristics making them ideally suited to play a pivotal role in the final stage of protein digestion. |
| first_indexed | 2024-03-06T20:31:13Z |
| format | Journal article |
| id | oxford-uuid:311ba14c-5ee7-4d90-a2d0-d68702702e8f |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T20:31:13Z |
| publishDate | 1975 |
| record_format | dspace |
| spelling | oxford-uuid:311ba14c-5ee7-4d90-a2d0-d68702702e8f2022-03-26T13:05:48ZIntestinal surface peptide hydrolases: identification and characterization of three enzymes from rat brush border.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:311ba14c-5ee7-4d90-a2d0-d68702702e8fEnglishSymplectic Elements at Oxford1975Wojnarowska, FGray, GPeptide hydrolases were solubilized from rat small intestinal brush border by papain and separated by Sephadex G-200 chromatography, velocity gradient ultracentrifugation and polyacrylamide disc electrophoresis and designated according to approximate molecular size from sedimentation studies. Peptidases I (apparent Mr 230 000) and II (apparent Mr 160 000) are oligopeptidases with maximum specificity for tripeptides with identical pH optima (7.5) and similar apparent Km with L-Leu-Gly (I, 0.60 MM; II, 0.76 mM). L-Leucyl-beta-naphthylamide is a competitive inhibitor of both enzymes. Concentration of peptidase II produced partial conversion to peptidase I on polyacrylamide disc electrophoresis. The third peptide hydrolase (III, Mr 120 000) is a dipeptidase with pH optimum 8.5 and apparent Km for L-Leu-Gly of 0.65 mM. These peptide hydrolases were inhibited appreciably (37-59%) by 0.2 M glycine/NaOH, Tris - HCl or Tris - glycine buffers. EDTA (5 mM) completely inhibited these enzymes but all activity was restored by dialysis against buffer without divalent ions. Subsequent addition of Mg2+, Mn2+, Co2+ or Zn2+ (1-2 mM) inhibited peptidases I and II variably (4-81%) depending upon the substrate and buffer used. In contrast peptidase III was activated slightly by metal ions (5-20%). These peptide hydrolases are strategically located at the intestinal lumen-cell interface and possess biochemical characteristics making them ideally suited to play a pivotal role in the final stage of protein digestion. |
| spellingShingle | Wojnarowska, F Gray, G Intestinal surface peptide hydrolases: identification and characterization of three enzymes from rat brush border. |
| title | Intestinal surface peptide hydrolases: identification and characterization of three enzymes from rat brush border. |
| title_full | Intestinal surface peptide hydrolases: identification and characterization of three enzymes from rat brush border. |
| title_fullStr | Intestinal surface peptide hydrolases: identification and characterization of three enzymes from rat brush border. |
| title_full_unstemmed | Intestinal surface peptide hydrolases: identification and characterization of three enzymes from rat brush border. |
| title_short | Intestinal surface peptide hydrolases: identification and characterization of three enzymes from rat brush border. |
| title_sort | intestinal surface peptide hydrolases identification and characterization of three enzymes from rat brush border |
| work_keys_str_mv | AT wojnarowskaf intestinalsurfacepeptidehydrolasesidentificationandcharacterizationofthreeenzymesfromratbrushborder AT grayg intestinalsurfacepeptidehydrolasesidentificationandcharacterizationofthreeenzymesfromratbrushborder |