| Budget Amount *help |
¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1986: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1985: ¥1,400,000 (Direct Cost: ¥1,400,000)
|
|---|
| Research Abstract |
Eight proteins which react with anti-cystatin S antiserum were purified to the electrophoretically homogeneous state from human whole saliva (temporarily named cystatin SN, S2, S3, SA, S6, S7 and S8). Their amino terminal sequences and Ki values for ficin,papain and dipeptidyl peptidase I were studied. S4, S6 and S8 lack N-terminal 9, 7 and 4 residues of cystatin S, while cystatin SA and cystatin S7 have extension of 4 and 3 residues at its N-terminus respectively. All of them show inhibitory activity for ficin and papain but have different Ki values. As amino acid substitutions were observed in cased of cystatin SN and SA, sequence study of their whole structures were undertaken. Both of them appered to have 90% sequence homology with cystatin S. These results suggest that cystatin S, proteins with structures related colsely to cystatin S, and their degraded or elongated proteins constitute a family of cysteine proteinase inhibitor in saliva. Cysteine proteinase inhibitors having the wide difference in the activity as the result of amino acid substitutions are considered to serve for the regulation of proteinase activity in saliva and salivary glands and for protection of oral tissues from enzymic attack. The Ouchterlony method was used to study the distribution of the antigen in human body fluids (serum, urine, tear, whole saliva, submaxillary-sublingual saliva, parotid saliva). When specimens were tested without concentration, tear, whole saliva, and submaxillary-sublingual saliva gave the positive results.
|
