Most of the matrix protein that is deposited in enamel during the secretory stage is lost during the postsecretory development of enamel. This protein loss is preceded by marked decreases in the molecular weights of the matrix proteins. It has been postulated that this molecular weight decrease is accomplished by a proteolytic enzyme that is secreted with the matrix. A serine protease activity in developing enamel has been reported. In preliminary studies, we have isolated a proteolytic enzyme from embryonic bovine secretory enamel. This enzyme represents a small fraction of the total matrix protein, and it has very low activity until it is separated from the bulk of the protein by affinity chromatography. The enzyme calcium-activated. This project is designed to further characterize this enzyme and to study its effect on developing enamel matrix.
The specific aims are as follows: (1) to purify the serine protease and to determine the specificity of bonds cleaved by this enzyme using model substrates and enamel matrix; (2) to determine whether the enzyme hydrolyzes amelogenins, enamelins, or both; (3) to determine whether the enzyme is secreted as a protenzyme or with an inhibitor; and (4) to determine whether inhibitors of the enzyme inhibit the in vitro loss from enamel of previously synthesized matrix proteins.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE006952-02
Application #
3220443
Study Section
Oral Biology and Medicine Study Section (OBM)
Project Start
1984-07-01
Project End
1987-06-30
Budget Start
1985-07-01
Budget End
1986-06-30
Support Year
2
Fiscal Year
1985
Total Cost
Indirect Cost
Name
University of North Carolina Chapel Hill
Department
Type
Schools of Dentistry/Oral Hygn
DUNS #
078861598
City
Chapel Hill
State
NC
Country
United States
Zip Code
27599