TY - JOUR
T1 - Aminopeptidase activity in human nasal mucosa
AU - Ohkubo, Kimihiro
AU - Baraniuk, James N.
AU - Hohman, Robert
AU - Merida, Marco
AU - Hersh, Louis B.
AU - Kaliner, Michael A.
PY - 1998
Y1 - 1998
N2 - Background: Aminopeptidases activate bradykinin and degrade many inflammatory peptides. Objective: The objective of this study was to identify the types of aminopeptidase activities in human nasal mucosa. Methods: Human nasal mucosa was homogenized (n = 12), and cytoplasmic (S2) and membrane- rich (P2) fractions were obtained. Several aminopeptidase (Ap) activities were defined by (1) substrate specificity with leucine-enkephalin (leu-Ap) and alanine-nitroanilide (ala-Ap), (2) inhibitor studies with puromycin and bestatin, (3) enzyme activity histochemistry (zymography), (4) immunohistochemistry, and (5) gel electrophoresis. Human volunteers had methacholine, histamine, and allergen nasal provocations to determine the mechanisms controlling nasal aminopeptidase secretion in vivo. Results: P2 was the largest reservoir of puromycin-resistant aminopeptidase activity (630 pmol leu-enk/min/mg protein). S2 contained 32 pmol leu-enk/min/mg activity, with 80% representing puromycin-resistant activity and 20% puromycin- sensitive aminopeptidase (PS-Ap). Ala-Ap was detected in both P2 and S2 fractions and was localized by zymography to epithelial and gland cells. Anti-rat brain-soluble PS-Ap IgG detected immunoreactive material in epithelium, glands, and endothelium. In nasal provocation studies, leu-AP correlated with glandular exocytosis but not vascular leak. Conclusions: The predominant aminopeptidase in human nasal epithelial and submucosal gland cells was membrane-bound puromycin-resistant aminopeptidase. A novel soluble puromycin-resistant aminopeptidase and lower amounts of soluble PS-Ap were also detected.
AB - Background: Aminopeptidases activate bradykinin and degrade many inflammatory peptides. Objective: The objective of this study was to identify the types of aminopeptidase activities in human nasal mucosa. Methods: Human nasal mucosa was homogenized (n = 12), and cytoplasmic (S2) and membrane- rich (P2) fractions were obtained. Several aminopeptidase (Ap) activities were defined by (1) substrate specificity with leucine-enkephalin (leu-Ap) and alanine-nitroanilide (ala-Ap), (2) inhibitor studies with puromycin and bestatin, (3) enzyme activity histochemistry (zymography), (4) immunohistochemistry, and (5) gel electrophoresis. Human volunteers had methacholine, histamine, and allergen nasal provocations to determine the mechanisms controlling nasal aminopeptidase secretion in vivo. Results: P2 was the largest reservoir of puromycin-resistant aminopeptidase activity (630 pmol leu-enk/min/mg protein). S2 contained 32 pmol leu-enk/min/mg activity, with 80% representing puromycin-resistant activity and 20% puromycin- sensitive aminopeptidase (PS-Ap). Ala-Ap was detected in both P2 and S2 fractions and was localized by zymography to epithelial and gland cells. Anti-rat brain-soluble PS-Ap IgG detected immunoreactive material in epithelium, glands, and endothelium. In nasal provocation studies, leu-AP correlated with glandular exocytosis but not vascular leak. Conclusions: The predominant aminopeptidase in human nasal epithelial and submucosal gland cells was membrane-bound puromycin-resistant aminopeptidase. A novel soluble puromycin-resistant aminopeptidase and lower amounts of soluble PS-Ap were also detected.
KW - Aminopeptidase M
KW - Bradykinin
KW - Enkephalin-degrading aminopeptidase
KW - Glandular secretion
KW - Puromycin sensitive aminopeptidase
KW - Rhinitis
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U2 - 10.1016/S0091-6749(98)70013-2
DO - 10.1016/S0091-6749(98)70013-2
M3 - Article
C2 - 9819290
AN - SCOPUS:0031725003
SN - 0091-6749
VL - 102
SP - 741
EP - 750
JO - Journal of Allergy and Clinical Immunology
JF - Journal of Allergy and Clinical Immunology
IS - 5
ER -