The structure and activities of theostatins A-C,highly cytotoxic polypeptides from the marine sponge Theonella swinhoei.
Project/Area Number |
05454096
|
Research Category |
Grant-in-Aid for General Scientific Research (B)
|
Allocation Type | Single-year Grants |
Research Field |
Fisheries chemistry
|
Research Institution | The University of Tokyo |
Principal Investigator |
FUSETANI Nobuhiro The University of Tokyo.Faculty of Agriculture.Professor., 農学部, 教授 (70012010)
|
Co-Investigator(Kenkyū-buntansha) |
MATSUNAGA Shigeki The university of Tokyo.Faculty of Agriculture.Assistant Professor., 農学部, 助手 (60183951)
|
Project Period (FY) |
1993 – 1994
|
Project Status |
Completed (Fiscal Year 1994)
|
Budget Amount *help |
¥6,900,000 (Direct Cost: ¥6,900,000)
Fiscal Year 1994: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1993: ¥5,700,000 (Direct Cost: ¥5,700,000)
|
Keywords | Cytotoxic / Polypeptides / Marine sponge / Unusual amino acids / Absolute configuration / Conformation / beta-helix / Pore-forming / 二次元NMR / 立体 / Theonella swinhoei / ペプチド / アミノ酸分析 / 2次元NMR / FAB-MS |
Research Abstract |
Highly cytotoxic polypeptides, polytheonamides A-C,have been isolated from the marine sponge Theonella swinhoei. The component amino acids of polytheonamides A-C were identified by amino acid analysis and NMR data of the acid hydrolysates. Their sequences were determined by interpretation of 2D NMR date. Polytheonamides are 48-residue polypeptides with N-terminus blocked by a carbamoyl group, and contain unusual amino acids such as t-Leu, betaMeIle, betaOHVal, betaOHAsm, betaMeGln, and OH-t-Leu. The absolute configuration of each amino acid residue in polytheonamide B were determined by chiral chromatographies of the partial acid hydrolysates. Interestingly, the sequence is a strictly alternating DL. NH_2CO-Gly-L-betaMeIle -Gly-L -t-Leu-D-t-Leu-L-t-Leu-D-Ala-L-t-Leu-D-t-Leu-L-Ala-Gly-L-Ala-D-t-Leu-L-Ala-D-Asm-betaOHVal-Gly-L-Ala-Gly-L-t-Leu-D-Asm-betaMeGln-betaOHVal-L-Ala-Gly-Gly-D-Asm-L-Ile-D-betaOHAsm-L-t-Leu-D-betaOHVal-Gly-D-Asm-L-Ile-D-Asm-L-Val-D-betaOHAsm-L-Ala-D-Asm-L-Val-D-Ser-L-Val-D-Asn-OH-t-Leu-D-Asn-L-Gln-L-Thr-D-aThr The NMR and CD spectra measured in a 1 : 1 mixture of chloroform and methanol indicated that polytheonamide B adopted certain secondary structure in this solvent. The DADAS90 calculations of the conformation in this solvent based on the constraints obtained by 2D NMR analyzes revealed that it formed a right-handed beta-helix. This is similar to that reported for the pore-forming peptide, gramicidin A.Therefore, polytheonamide B likely forms a pore in lipid bilayr as does gramicidin A.
|
Report
(3 results)
Research Products
(12 results)