Project/Area Number |
10672187
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Laboratory medicine
|
Research Institution | KOKUSAI GAKUIN SAITAMA JUNIOR COLLAGE (2000) Jikei University School of Medicine (1998-1999) |
Principal Investigator |
SUDO Kayoko KOKUSAI GAKUIN SAITAMA JUNIOR COLLAGE NUTRITION PROFESSOR, 助教授 (90115486)
|
Project Period (FY) |
1998 – 2000
|
Project Status |
Completed (Fiscal Year 2000)
|
Budget Amount *help |
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2000: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1999: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1998: ¥1,100,000 (Direct Cost: ¥1,100,000)
|
Keywords | SERUM CHOLINESTERASE / VARIANT GENE / GENE EXPRESSION / MISSENSE MUTATION / 293 CELL / EXPRESSION VECTOR / FLUORIDE-RESISTANT / ONE POINT MUTATION / フカソーダ耐性 |
Research Abstract |
Several genetic variants of human serum butyrylcholinesterase (EC3.1.1.8 ; BCHE) have been reported to be associated with prolonged apnea after medication of the muscle relaxant drug succinylcholine. These BCHE variants were qualitatively identified by dibucaine number (DN) and fluoride number (FN). Atypical variant is phenotyped by resistance to inhibition by dibucaine (low DN) and fluoride resistant variants were phenotyped by resistance to inhibition by NaF (low FN and DN). Two types of fluoride-resistant gene have been reported. They were Fluoride-1 and -2 variants which were Thr243Met and Gly390Val, respectively. Even after screening several times for the atypical BCHE (Asp70Gly), and two kinds of the fluoride-resistant variants in the Japanese population, we could not find these mutations (our personal data). Therefore, we considered these differences might have originated from ethnic difference. We found an individual homozygous for L330I mutation (alteration from leucine to isoleucine at codon 330) who showed reductions of enzymatic activity, DN and FN.His DN and FN showed FS phenotype rather than FF.The L330I mutation has never been reported in foreign countries. By expression of the recombinant BCHE protein in human fetal kidney cells, The BCHE L330I variant showed low enzymatic activity, low DN and FN.Therefore, we conclude the BCHE L330I mutation is a Japanese type fluoride-resistant gene. We also have expressed recombinant ChE proteins (wild type, 330V and 330S). All of the recombinants with amino acid substitutions at codon 330 caused not only a reduction of BCHE activity but also the abnormal DN and FN.The degrees of the reduction were almost the same. We conclude that the mutant recombinant BCHEs at codon 330 possibly have the properties of the fluoride-resistant gene and suggest that codon 330 is important to interact with substrate and sodium fluoride.
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