|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1991 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1990 : ¥1,500,000 (Direct Cost : ¥1,500,000)
It was found that a metalloproteinase from Penicillium citrinum has a specificity unique from those of other metalloproteinases on nuclear basic proteins and oxidized insulin B-chain.
The enzyme was found to contain 1 gram-atom zinc per mole of enzyme with the molecular weight of 17, 000. About 95% of the amino acid sequence of the enzyme was determined. The circular dichroism(CD)of the holo- and apo-enzymes has been investigated. One gram-atom of zinc was essential component of the enzyme not only the activity but also the conformation.
The enzyme was specifically active on basic nuclear protein& such as clupeine, salmine and histone at pH 7.0. The initial site of cleavage on the oxidized insulin B-chain by the proteinase was between Tyrl6-Leul7, and additional sites, Glul3-Alal4 and Alal4-Leul5 were noted. Hydrolyses of small peptides consisting 5 - 13 amino acids such as bradykinin, dynorphin-A, alpha-neoendorphin, neurotensin, luteinizing hormone releasing hormone, alpha-melanocyt. e stimulating hormone, substance P and chicken brain pentapeptide were noted.