| Project/Area Number |
12450368
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Synthetic chemistry
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| Research Institution | Fukui National College of Technology |
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Principal Investigator |
OGOSHI Hisanobu Fukui National College of Technology, President, 校長 (90026188)
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| Co-Investigator(Kenkyū-buntansha) |
HAYASHI Takashi Depertment of Chemistry and Biolchemistry, Graduate School of Engineering, Kyushu University, Associate Professor, 大学院・工学研究科, 助教授 (20222226)
TSUDA Yoshihiro Fukui National College of Technology, Depertment of Chemistry and Biology Engineering, Associate Professor, 物質工学科, 助教授 (60216463)
MATSUI Syuichi Fukui National College of Technology, Depertment of Chemistry and Biology Engineering, Professor, 物質工学科, 教授 (60042975)
AOYAGI Katsuhiro Fukushima National College of Technology Department of Chemistry and Biochemistry, Professor, 物質工学科, 教授 (40150940)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥14,900,000 (Direct Cost: ¥14,900,000)
Fiscal Year 2001: ¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 2000: ¥11,000,000 (Direct Cost: ¥11,000,000)
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| Keywords | Protein Reconstitution / Heme Protein / N-Alkylsubstituted Porphyrin / Myoglobin / Heme Abnormal Metabolism / Normal / Reverse / Heme Pocket / NMR |
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| Research Abstract |
Cobalt(II)complexes of N_A-ethyl and N_B-ethylmesoporphyrin dimethylester(the isomers with ethyl group on the A ring and B rings) have been prepared to elucidate the reaction mechanism of abnormal heme metabolism. The reconstituted myoglobins with the cobalt(II) complexes of N-ethylmesoporphyrin have been characterized by 1^H-NMR measurements.
The reconstitution of apomyoglobin with 1.6 equivalent of Co(II)complexes of N_A-and N_B-ethylmesoporphyrin affordd stable myoglobins ((N_A-C_2H_5Meso)Co(II) and (N_B-C_2H_5Meso)Co(II)-Mb. The 1^H-NMR spectrum showed three signals at -34.75 ppm, -36.63 ppm and -48.61 ppm assigned to the methyl group of N-ethyl group, respectively.
The chemical shifts of these signals were agreement with those of myoglobins reconstituted with (N_A-C_2H_5 Meso Co(II) and (N_B-C_2H_5Meso)Co(II), individually. The N-alkylmesoporphyrin coordinates with myoglobin in normal or reverse orientation because the heme pocket of yoglobin recognizes the sequence of side chains o
… More
f N-alkylmesoporphyrin. The signal at -34.75, -36.63 and -48.61ppm is assigned to the NA-CzHs of reverse orientation, N_A-C_2H_5 of normal orientation and N_B-C_2H_5 of reverse orientation, respectively. It seems that the steric repulsion of Na-ethyl group with isopropyl group of Val 68 in myoglobin is larger than that of N_A-ethyl group is responsible for the relative abundance of N_A-and N_B-ehyl group of reverse orientation(1 : 0.4). In addition, it seems that the relative abundance of N_A-ethyl group of reverse rientation and N_B-ethyl group of normal orientation (1 : 2) is dependent on the assumption that the N-ethylmesoporphyrin of normal orientation is referentially reconstituted with myoglobin because the heme pocket of myoglobin recognize the sequence of side chains of N-alkylmesoporphyrin.
It can be seen from these results that the apomyoglobin recognizes a pair of enantiomers of N-alkylmesoporphyrin by the asymmetric heme pocket, and that the steric repulsion of N-ethyl group with Val 68 play an important role in the asymmetric recognition. It seems reasonable to assume that the relative abundance of the regioisomers of N-alkylmesoporphyrin reconstituted with myoglobin is tendency to migrate to pyrolle nitrogen atom of alkyl group. Less
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