1997 Fiscal Year Final Research Report Summary
Research for properties of the expressed recombinant human serum cholinesterase variant
Project/Area Number |
08672651
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Laboratory medicine
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Research Institution | Jikei University School of Medicine |
Principal Investigator |
SUDO Kayoko Jikei University School of Medicine the medical department Lecturer, 医学部・臨床検査医学, 講師 (90115486)
|
Project Period (FY) |
1996 – 1997
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Keywords | dibucaine number / fluoride number (FN) / serum cholinesterase / missense mutation / human fetal kidney cells (293 cell) / expression / recombinant / transversion |
Research Abstract |
We have found individuals heterozygous for BCHE L330I from a low serum BCHE activity group and slightly low DN and FN group selected randomly from the population. A 63-year-old Japanese man showed low serum BCHE activity on health examination. Secondary hypocholinesterasemia due to agricultural chemical poisoming and severe hepatic dysfunction were ruled out. The phenotyping analysis revealed a reduced dibucaine number (DN) and an esxpecially low fluoride number (FN), similar to an FS phenotype. Although the fluoride-resistant gene has been reported to be caused by T243M and G390V in Caucasian, we could not find these mutations in Japanese containing this case. A homozygousmissense mutation, a T to A transversion at nucleotide 988, was identified in his BCHE gene. This mutation resulted in the replacement of leusine by isoleucine at codon 330 (L339I). It is important to demonstrate whether the abnormal DN and FN are originated from the BCHE L330I mutation alone or there are some other genetic or modifying factors. DN and FN of recombinant BCHE (L339I) secreted by human fetal kidney cells were compared to recombinant wild-type (usual gene) BCHE and normal serum BCHE.The individual nucleotide substitution characterizing the BCHE L330I variant was introduced into the pRcCMV plasmid containing usual BCHE using PCR.By expression of the recombinant BCHE protein in human fetal kidney cells (293 ; JCRB9068、ATCC CRL1573) which were transformed with purified pRcCMV-BCHE plasmid, we showed that the BCHE L330I variant resulted in low enzymatic activity and low DN and FN.These results showed this amino acid substitution of BCHE,Leu330 to Ile, really caused the abnormal DN and FN.We conclude the BCHE L330I mutation is a fluoride-resistant gene, a Japanese type fluoride-resistant gene.
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Research Products
(6 results)