Search

Your search keyword '"Sakata, Kazuki"' showing total 129 results
Start Over Author "Sakata, Kazuki" Publication Year Range Last 50 years
129 results on '"Sakata, Kazuki"'

2. The ATPase activity of ABCA1 is increased by cholesterol in the presence of anionic lipids.

Author

Sakata, Kazuki, Kioka, Noriyuki, Ueda, Kazumitsu, and Kimura, Yasuhisa

Subjects
*ATP-binding cassette transporters, *ADENOSINE triphosphatase, *CHOLESTEROL, *LIPIDS, *APOLIPOPROTEIN A, *HIGH density lipoproteins
Abstract

High-density lipoprotein (HDL) transports excess cholesterol from peripheral tissues back to the liver, and plasma HDL levels are inversely related to cardiovascular disease incidence. ATP-binding cassette A1 (ABCA1) is a member of the ABC protein superfamily, and generates nascent HDL, which consists of several hundreds of phospholipids and cholesterol wrapped by apolipoprotein A-I (apoA-I). However, it remains unclear whether cholesterol is a transport substrate of ABCA1. Since ATP hydrolysis of ABC proteins is typically increased by their transport substrates, we characterized the effects of cholesterol on the ATPase activity of purified ABCA1 using liposomes of various lipid compositions. ABCA1 showed substantial ATPase activity (20–30 nmol |$\cdot$| min−1 |$\cdot$| mg−1) only in liposomes containing anionic lipids, including phosphatidylserine. Cholesterol increased the ATPase activity by 1.6- to 3-fold in the presence of anionic lipids. Moreover, phosphatidylserine addition to BHK/ABCA1 cells increased phosphatidylcholine and cholesterol efflux to apoA-I. Next, we investigated the sterol specificity of ABCA1. The ATPase activity of ABCA1 was strongly enhanced by desmosterol and zymosterol, similar to cholesterol. In contrast, 7-dehydrocholesterol and lathosterol weakly increased the ATPase activity, and no increase was observed with stigmasterol or brassicasterol. These findings suggest that ABCA1 transports cholesterol and prefers cholesterol over plant sterols as a transport substrate. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

7. Development of 2Chip IPCAM

Author

Ishikura, Hisashi, Fujii, Yoshiyuki, Sakata, Kazuki, Tsukaoka, Hideki, Yamamoto, Takayuki, and Yasui, Katsuaki

Published
2003

31. Development of Image Processing Camera (IPCAM).

Author

Valldorf, Jürgen, Gessner, Wolfgang, Fujii, Yoshiyuki, Sakata, Kazuki, Tsukaoka, Hideki, Ishikura, Hisashi, Yamamoto, Takayuki, and Yasui, Katsuaki

Abstract

This paper outlines methods of cost reduction and downsizing of our Image Processing Camera (IPCAM) intended for use in lane departure warning system or lane keeping system. These systems have potential needs in the society because they may be abele to reduce fatal traffic accidents. But we faced two issues to solve before the popularisation of these systems. First one was how to reduce the cost of image-processing camera currently consisting of many expensive devices. Second one was how to improve the lane detection performance and the accuracy. Our attempt to provide solutions to the above-described problems began with innovation of hardware architecture for image processing, based on our unique algorism for lane detection. We realized that pre-processor for image processing and external memory ware eliminated by the innovation. In addition, an adoption of 1 chip CMOS imager was realized by long exposure within those systems delay. Moreover we could materialize conversion from glass lens into plastic one. Then we successfully devised the way to operate an image processing only with a general- purpose microcomputer and an image sensor. Now the volume of the camera is just 50cm3. Compared with costly conventional ones, our image-processing camera is far smaller and low cost. In this paper, we are going to describe our revolutionary image-processing camera aimed for wide diffusion. [ABSTRACT FROM AUTHOR]

Published
2003
Full Text
View/download PDF

34. Biotransformation of (+)-cycloisolongifolol by plant pathogenic fungus Glomerella cingulata.

Author

Miyazawa, Mitsuo and Sakata, Kazuki

Abstract

The biotransformation of terpenoids using the plant pathogenic fungus as a biocatalyst to produce useful novel organic compounds was investigated. The biotransformation of sesquiterpen alcohol, (+)-cycloisolongifolol (1) was investigated using plant pathogenic fungus Glomerella cingulata as a biocatalyst. Compound 1 gave one major metabolic product and a number of minor metabolic products. Major product was dehydration at the C-8 position to (+)-dehydrocycloisolongifolene (2). The structure of the product was determined by their spectroscopic data. Glomerella cingulata gave dehydration in the specifically and over 70% conversion. [ABSTRACT FROM AUTHOR]

Published
2007
Full Text
View/download PDF

46. αChiral Acetylenes Having an AllCarbon Quaternary Center: Phase Transfer Catalyzed Enantioselective αAlkylation of αAlkylαalkynyl EstersThis work was partially supported by a GrantinAid for Scientific Research from the MEXT Japan.

Author

Hashimoto, Takuya, Sakata, Kazuki, and Maruoka, Keiji

Abstract

Going through the phases: The title reaction was found to proceed by an initial basemediated isomerization to allenyl esters and subsequent phase transfer catalyzed alkylation at the αposition of the ester see scheme.

Published
2009
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results