Chul Yong Song

Analysis of human amniotic membrane components as proteinase inhibitors for development of therapeutic agent for recalcitrant keratitis

Summary Transplantation of preserved amniotic membrane has been known to be effective in clinical treatment of severely damaged ocular surfaces. Amniotic membrane showed inhibitory effects on serine proteinase such as proteinase of A. castellanii , trypsin, and plasmin and metallo- proteinase, collagenase. However, elastase and proteinases of P. aeruginosa, S. aureus , and A. fumigatus were not inhibited by amniotic membrane. In Western blot analysis, at least five proteinase inhibitors including α1-antitrypsin, α1-antichymotrypsin, inter-α1-trypsin inhibitor, α2-macroglobulin and α2-antiplasmin, were detected in amniotic membrane. These suggest that the therapeutic effect of amniotic membrane, at least in part, may be due to the roles of proteinase inhibitors in the amniotic membrane. These inhibitors may contribute the therapeutic effects of amniotic membrane by inhibiting proteinases which can cause persistent corneal destruction by proteolytic degradation of cornea.

Clonorchis sinensis: purification and characterization of a cysteine proteinase from adult worms.

1. Adult Clonorchis sinensis, the Chinese liver fluke, is known to migrate to the bile ducts of its mammalian host and cause significant pathology. 2. An acidic, thiol-dependent proteinase with a native mol. wt of approximately 18,500 was purified to homogeneity using ion-exchange chromatography and gel filtration chromatography. By SDS-polyacrylamide gel electrophoresis, the mol. wt of the enzyme was estimated to be 15,000. 3. The enzyme was similar to cathepsin B-like cysteine proteinases based on pH optimum, substrate specificity, and inhibitor sensitivity. 4. Antisera from human clonorchiasis and C. sinensis-infected rabbits reacted in immunoblots with the partially purified proteinase. The C. sinensis proteinase may be useful for serodiagnosis of clonorchiasis.

Cysteine proteinase activity in various developmental stages of Clonorchis sinensis: A comparative analysis

1. Cysteine proteinase activity in acidic extracts of various developmental stages of Clonorchis sinensis (metacercariae, 1-, 2-, and 3-month old worms) was examined. All the activities were maximum at acidic pH and showed inhibitor susceptibilities similar to the vertebrate cysteine proteinases. 2. Specific activity of cysteine proteinase(s) was highest in metacercariae with either CBZ-phe-arg-AFC or Azocoll as the substrate. The immature and mature worms had similar (but less than metacercariae) levels of activity. 3. A soluble cysteine proteinase with a native molecular weight of approximately 20,000 +/- 1414 was partially purified from 1-, 2-, and 3-month worms. The molecular weight of similar activity in metacercariae was approximately 32,000. 4. Results suggest developmental regulation of cysteine proteinase activity in the life cycle of C. sinensis.