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Your search keyword '"Abe, Junichi"' showing total 8 results
Start Over Author "Abe, Junichi" Journal neurochemical research
8 results on '"Abe, Junichi"'

6. Structural Specificity for the Inhibitory Effect of Calmodulin on Specific 125I-Omega-Conotoxin GVIA Binding.

Author

Ichida, Seiji, Abe, Junichi, Zhang Yu-An, Junichi, Minam, Takeshi, Wada, Tetsuyuki, Yazawa, Michio, and Sohma, Hitoshi

Subjects
CALMODULIN, ENZYME inhibitors, BRAIN diseases, TETRAHYDROISOQUINOLINES, CHIMERAS (Botany), PROTEIN binding
Abstract

To clear the structural specificity of calmodulin (CaM) on the specific [SUP125]I-ω-CTX binding to crude membranes from whole chick brain, the following experiments were investigated in this study: (i) the attenuating effect of semisynthetic tetrahydroisoquinoline derivatives on the inhibitory effect of Ca[SUP2+]/CaM, (ii) the effects of chimeras of yeast and chicken Ca[SUP2+]/CaM, and (iii) the effects of Ca[SUP2+]-binding proteins (such as troponin c, S 100 a and b, and annexin I, III-V). The inhibitory effect of Ca[SUP2+]/CAM was attenuated by isoquinoline derivatives (PX 28, 34, 216, 224, and CPU57) and a CAM antagonist W-7. PX 34, a typical synthesized isoquinoline derivative, showed the attenuating effect in a dose-dependent manner. The ED[SUB50] value for the attenuating effect of PX 34 was about 20 μM, which is similar to that of W-7 reported previously. Some chimeric CAMs such as YC 51-53 (which are close to the properties of vertebrate CaM) showed a significant inhibitory effect on the specific [SUP125]I-ω-CTX binding, but YC 129 and 130 (which retain the properties of yeast CAM), troponin c, S100 a, b, and annexin I, III-V had no effect on the specific [SUP125]I-ω-CTX binding. These results suggest that the characteristic structure containing the EF-hand structure of CAM itself is needed to cause the inhibitory effect on the specific [SUP125]I-ω-CTX binding. [ABSTRACT FROM AUTHOR]

Published
2003

7. A Confirmation of [sup 125]I-w-Conotoxin Labeled Sites in a Crude Membrane Fraction from Chick Brain as the Alpha[sub 1] Subunit of N-Type Calcium Channels.

Author

Wada, Tetsuyuki, Abe, Junichi, and Minami, Takeshi

Subjects
CALCIUM antagonists, BRAIN, CHICKS, NEUROCHEMISTRY
Abstract

Reports on the presence of omega-conotoxin GVIA labeled sites in a crude membrane fraction of the chick brain. Use of omega-conotoxin as a selective blocker for a nitrogen-type calcium[sup 2+] channel; Key applications on the omega-conotoxin in biochemical and pharmacological experiments; Implications on neurochemical research.

Published
2003

8. A Confirmation of 125I-ω-Conotoxin Labeled Sites in a Crude Membrane Fraction from Chick Brain as the α1Subunit of N-Type Calcium Channels

Author

Wada, Tetsuyuki, Abe, Junichi, Minami, Takeshi, Masuko, Takashi, and Ichida, Seiji

Abstract

Omega-conotoxin GVIA (ω-CTX), as a selective blocker for an N-type Ca2+channel, has been conveniently used in many molecular biochemical and pharmacological experiments. There has been little elucidation of 125I-ω-CTX binding sites (mainly the 135-kDa band) in the crude membranes from chick brain, although the characteristics of specific 125I-ω-CTX binding and labeling sites in chick brain membranes have been investigated in our previous research. In this work, our goal is to further identify 125I-ω-CTX labeling sites in chick brain membranes by using anti-B1Nt antibodies (against the N-terminal segment B1Nt of N- or P-type Ca2+channel α1-subunits). The 125I-ω-CTX–labeled sites in chick brain membranes could be solubilized and immunoprecipitated by using an anti B1Nt antibody. The molecular weight of the immunoprecipitated protein was determined as 135 kDa, which is inconsistent with that of the specific 125I-ω-CTX binding protein reported previously. Moreover, the 125I-ω-CTX–labeled protein could be purified by the method of preparative SDS-PAGE and recognized by anti-B1Nt antibodies in Western blotting analysis. These results indicated that anti-B1Nt antibodies could truly recognize 125I-ω-CTX–labeled sites as the main band of 135 kDa from chick brain membranes, and the ω-CTX–labeled site (mainly the 135-kDa band) should be N-type Ca2+channel α1-subunits.

Published
2003
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