Biomaterial Database

Protease deficiency in plasma of patients with cystic fibrosis. Reduced reaction of 4-methylumbelliferylguanidinobenzoate with plasma of patients with cystic fibrosis. 1979

M Walsh-Platt, and G J Rao, and H L Nadler

Protease activity in plasma is assayed using 4-methylumbelliferylguanidinobenzoate. The assay is modified by carrying out the reaction in the presence and absence of benzamidine, a competitive inhibitor of trypsin-like proteases. The parameters of the assay are described in detail. Using this assay, our earlier demonstration of a deficiency of protease activity in plasma of patients with cystic fibrosis is confirmed. The activity, corrected for the nonspecific hydrolysis of 4-methylumbelliferylguanidinobenzoate by benzamidine, is expressed as nanomoles of 4-methylumbelliferone released per milliliter plasma. Under standard conditions, the activity in plasma activated with chloroform-ellagic acid was 127.2 +/- 23.1 in 7 controls, 70.4 +/- 11.7 in 11 obligate heterozygotes, and 48.7 +/- 16.6 in 12 patients with cystic fibrosis. Identical results were obtained when unactivated plasma was used. These data demonstrate that the judicious use of specific inhibitors such as benzamidine might be useful in assaying low levels of protease activity in crude systems.

UI	MeSH Term	Description	Entries
D010447	Peptide Hydrolases	Hydrolases that specifically cleave the peptide bonds found in PROTEINS and PEPTIDES. Examples of sub-subclasses for this group include EXOPEPTIDASES and ENDOPEPTIDASES.	Peptidase,Peptidases,Peptide Hydrolase,Protease,Proteases,Proteinase,Proteinases,Proteolytic Enzyme,Proteolytic Enzymes,Esteroproteases,Enzyme, Proteolytic,Hydrolase, Peptide
D002648	Child	A person 6 to 12 years of age. An individual 2 to 5 years old is CHILD, PRESCHOOL.	Children
D003550	Cystic Fibrosis	An autosomal recessive genetic disease of the EXOCRINE GLANDS. It is caused by mutations in the gene encoding the CYSTIC FIBROSIS TRANSMEMBRANE CONDUCTANCE REGULATOR expressed in several organs including the LUNG, the PANCREAS, the BILIARY SYSTEM, and the SWEAT GLANDS. Cystic fibrosis is characterized by epithelial secretory dysfunction associated with ductal obstruction resulting in AIRWAY OBSTRUCTION; chronic RESPIRATORY INFECTIONS; PANCREATIC INSUFFICIENCY; maldigestion; salt depletion; and HEAT PROSTRATION.	Mucoviscidosis,Cystic Fibrosis of Pancreas,Fibrocystic Disease of Pancreas,Pancreatic Cystic Fibrosis,Pulmonary Cystic Fibrosis,Cystic Fibrosis, Pancreatic,Cystic Fibrosis, Pulmonary,Fibrosis, Cystic,Pancreas Fibrocystic Disease,Pancreas Fibrocystic Diseases
D006146	Guanidines	A family of iminourea derivatives. The parent compound has been isolated from mushrooms, corn germ, rice hulls, mussels, earthworms, and turnip juice. Derivatives may have antiviral and antifungal properties.
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006923	Hymecromone	A coumarin derivative possessing properties as a spasmolytic, choleretic and light-protective agent. It is also used in ANALYTICAL CHEMISTRY TECHNIQUES for the determination of NITRIC ACID.	Imecromone,Methylumbelliferone,Resocyanine,4-Methylumbelliferone,7-Hydroxy-4-methyl-coumarin,Cholestil,Mendiaxon,4 Methylumbelliferone,7 Hydroxy 4 methyl coumarin
D001550	Benzamidines	Amidines substituted with a benzene group. Benzamidine and its derivatives are known as peptidase inhibitors.
D014361	Trypsin Inhibitors	Serine proteinase inhibitors which inhibit trypsin. They may be endogenous or exogenous compounds.	Trypsin Inhibitor,Inhibitor, Trypsin,Inhibitors, Trypsin
D014468	Umbelliferones	7-Hydroxycoumarins. Substances present in many plants, especially umbelliferae. Umbelliferones are used in sunscreen preparations and may be mutagenic. Their derivatives are used in liver therapy, as reagents, plant growth factors, sunscreens, insecticides, parasiticides, choleretics, spasmolytics, etc.	7-Hydroxycoumarins,Hydrangin,Skimmetin,7 Hydroxycoumarins