1995 Fiscal Year Final Research Report Summary
Trials for development of novel inhibitors for intracellular signaling.
| Project/Area Number |
06558095
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Structural biochemistry
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| Research Institution | Fukushima Medical College (1995)
Tokyo Metropolitan Institute of Gerontology (1994) |
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Principal Investigator |
HOMMA Yoshimi Fukushima medical college, Department of Biomolecular, Science, Professor, 医学部, 教授 (60192324)
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| Co-Investigator(Kenkyū-buntansha) |
YAMASAKI Moto-o Kyowa Hakko Co.Ltd., Tokyo Research Institute, Senior Investigator, 東京研究所, 主任研究員
HOMMA Miwako Tokyo Medical and Dental University, Department of Hygiene and Oncology, Researc, 医学部, 助手 (40192538)
OHMI Shinobu University of Tokyo, Institute of Medical Sciences, Associate Professor, 医科学研究所, 助教授 (20160046)
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| Project Period (FY) |
1994 – 1995
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| Keywords | intracellular signaling / inositol phospholipid / phosphdipase C / autoinhibitor / synthetic peptide / acylation |
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| Research Abstract |
PLC-gamma possesses a phospholipase C inhibitor (PCI) region adjacent to its SH2 and SH3 motifs that strongly suppresses the PIP_2 hydrolyzing activity of purified PLC isoforms in vitro. Synthetic peptides identical to the amino acid sequence of the PCI region (PCI peptides) inhibit PIP_2 hydrolysis induced by each PLC isoforms. It has been demonstrated that the acylation of various synthetic peptides enhances their permeability to the plasma membrane, rendering the peptides potentially specific effectors or inhibitors inside intact cells. Based on this information, we synthesized various kinds of acylated PCI peptides, and examined their effects on intracellular PLC activity using normal fibroblasts and cancer cells. In this study, we obtained following results. 1) We synthe sized 50 kinds of acylated PCI peptides, among which 35 acylated peptides were used in this study. 2) Acylation of the PCI peptides did not alter their specific secondary structure which is conserved among all PCI peptides and probably required for PLC inhibition, and strongly enhanced their PLC inhibitory potency. Acylation of the peptides significantly enhanced their permeability to the plasma membrane, and preincubation of cells with acylated peptides resulted in inhibition of intracellular PLC activation. The inhibitory effects of the peptides varied among types of acylation.
4) N-myristoylated PCI peptides, one of the most potent PCI peptides, suppressed the ligand-dependent IP_3 formation in 3Y1 cells (ED_<50>=1muM) and growth of some carcinoma cells. 5) This study indicated a possibility to produce more potent PCI peptides by combination of various N- and C-terminal modifications and a difficulty to produce synthetic compounds structurally related to PCI peptides.
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