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)
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Research Abstract |
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.
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