今日もArt & Science

写真付きで日記や趣味を勝手気ままに書くつもり!
徒然草や方丈記の様に!
あるいは寺田寅彦の様に!

広告

※このエリアは、60日間投稿が無い場合に表示されます。記事を投稿すると、表示されなくなります。

ユビセミキノンの機能(1)

2014-03-21 13:16:30 | ラジカル

705pxcomplex_i_svg(クリックで拡大)
図1 呼吸鎖複合体I内の電子伝達機構の模式図。図中Q はユビキノンを表す。

ユビキノン(UQ:図1)はミトコンドリア内膜や原核生物の細胞膜に存在する電子伝達体の1つで、呼吸鎖複合体I内の電子伝達の仲介を果たしている。ベンゾキノンの誘導体であり、比較的長いイソプレン側鎖を持つので、その疎水性のために膜中に保持される。酸化還元電位 (Eo') は+0.10V。ウシ心筋ミトコンドリア電子伝達系の構成成分として1957年に発見された。還元型のユビキノンは『ユビキノール』とも呼ばれる。また、補酵素Q、コエンザイムQ10、ビタミンQ、CoQ10、ユビデカレノン等と呼ぶこともある。

UQの酸化還元に関わるベンゾキノン誘導体部位はパラ型に酸素原子が結合しており、C2にはメチル基、C5,C6にはメトキシ基が結合している。C3にはイソプレン側鎖が結合しており、生体膜中に保持されるように長い炭素鎖を持つ。

Ubiquinone構造式

図1 ユビキノン(UQ)の構造。

イソプレン側鎖の数(n=)は高等動物では10、下等動物では6~9であり、イソプレン側鎖が長くなればなるほど黄橙色を呈するようになる。なおn=10のユビキノンは『UQ10』と略記される。ユビキノンは一電子還元を受けて中間型(ユビセミキノン)となる。中間型はプロトンキノンサイクル機構で機能している。ユビキノンの酸化還元様式を以下に示す。

Ubiquinoneredox.PNG

酸化型のユビキノンは275nmの波長の紫外光を吸収する。したがって、ユビキノンに電子伝達を行う酵素群の活性測定はこの波長に類する吸収帯を使用する。

ユビキノンはミトコンドリア内膜や原核生物の細胞膜から単離され、膜内の電子伝達に関与することが古くから知られており、特に、電子伝達系の呼吸鎖複合体I(NADH脱水素酵素)から呼吸鎖複合体III(シトクロムbc1複合体)への電子伝達に寄与している。

呼吸鎖複合体Iにおける反応

NADH + ユビキノン(UQox) → NAD+ + ユビキノール (UQred)

ユビキノンは日本では1970年代から医療用医薬品として軽度及び中等度のうっ血性心不全症状などに用いられてきた。また、複数の製薬メーカーが、一般用医薬品(OTC医薬品)・医薬部外品として、一般消費者向けの商品を発売している。安全性は比較的高く、米国ではコエンザイムQ10の名称でサプリメントとして広く用いられており、医師の処方箋なしに消費者が直接店頭などで購入できる。日本でも2001年に医薬品の範囲に関する基準(いわゆる「食薬区分」)が改正され、さらに2004年化粧品基準が改正されて、健康食品や化粧品への利用に道が開かれた。その結果、抗老化作用を訴求したユビキノン(コエンザイムQ10)含有の健康食品や化粧品がブームとなり、原材料の品薄で入手しにくいほどの人気を博していた時期があった。しかしながら、そのような薬効を臨床的に検討したデータはまだ乏しく、詳細な効果についてはまだ詳しくわかっていない。

2009年11月に、ユビキノンの抗酸化作用がマウスの老人性難聴の予防に効果があることを、東京大学が実験で明らかにした。それによると、人間にとっては1日20ミリグラムにあたる量のユビキノンを生後4ヶ月から与えられ続けてきたマウスは、人間の50歳に相当する生後15ヶ月の時点で、同じ月齢のマウスが45デシベル以上の音しか聞き取れないのに対し、12デシベルの小さい音を聞き取れるようになった。2013年7月16日に、小児性線維筋痛症発生の原因がユビキノンの欠乏にあることが、東京工科大学応用生物学部山本順寛教授らと、横浜市立大学医学部小児科との研究チームにより発見された。

ジャンル:
ウェブログ
コメント (49)   この記事についてブログを書く
« ちょっといっぷく55 早春賦 | トップ | 賀茂川にツバメが戻ってきた! »

49 コメント

コメント日が  古い順  |   新しい順
Fine way of describing, and pleasant piece of w... (?????????????)
2014-04-23 03:09:04
Fine way of describing, and pleasant piece of writing to obtain information regarding my presentation focus, which i am going to deliver in college.
It's actually a nice and helpful piece of i... (grow taller 4 idiots)
2014-06-27 08:58:21
It's actually a nice and helpful piece of info. I am glad that you shared this helpful info with us. Please keep us up to date like this. Thank you for sharing.
I'll immediately seize your rss as I can... (plan cul)
2014-06-27 22:14:38
I'll immediately seize your rss as I can't in finding your e-mail subscription link or newsletter service. Do you have any? Please permit me recognise in order that I may subscribe. Thanks.
Hello there! This blog post could not be writte... (rencontre Plan cul)
2014-08-07 10:11:18
Hello there! This blog post could not be written any better! Looking at this post reminds me of my previous roommate! He continually kept talking about this. I will forward this post to him. Pretty sure he's going to have a very good read. Thanks for sharing!
It's hard to find well-informed people for ... (best at home laser hair removal)
2014-08-16 09:05:26
It's hard to find well-informed people for this subject, but you sound like you know what you're talking about! Thanks
4 inputs in the rear panel, supports the brand ... (my view)
2014-08-24 21:01:37
4 inputs in the rear panel, supports the brand new Audio Return Channel (ARC). A single added advantage of the HDMI cable for audio or video transmission might be the blend of a great deal of cables into a single ""plug"" at each and every and every end. S video hdmi cable
Exactly Why Are Lace Top Wigs the most effective Wigs? (Stevenhoamn)
2017-03-23 03:51:32
There are lots of various types of wigs available on the market. Women wear wigs for many diverse reasons for occasion, to pay hair loss in certain Wigs For Black Women
locations to full hairloss as a result of health concerns. Choosing the right one could be frustrating at these kinds of times. One more reason most women use wigs would be to attain hairdos that are impossible to do with Human Hair Extensions
their own locks.

the lace front wig is one kind of wig. This wig has personal hairs which are hand sewn right into a lace materials that are identified only at the front portion of the wig. Manually stitches the hair Wigs For Women
in the lace front it gives the impact the hairs are increasing from the scalp. After you have the wig guaranteed into position, the lace substance is cut off of in the hair line with out Human Hair Wigs
reducing the knots. The lace can then be stuck into place and based on what sort of adhesive is used, may last from times to several weeks. Following gluing the lace straight down, beauty products does apply to conceal the lace. You won't be able to recognize in which the wig range will begin Halo Hair Extensions
which way you should have a all-natural searching hairpiece. Here is the extremely good reason why this is basically the best sort of wig you will discover.
Hair pieces Regarding African American Ladies - Classy However Affordable (JustinHom)
2017-04-01 00:05:10
Locks, as we all know, is actually Wigs For Black Women everybody's glorious wonder. In the past, for women who live slaved Wigs For Women regarding this, shelling out hundreds of thousands regarding money on hair treatments and items. Most of these merchandise work well with a other people's head of hair, however some women have head of hair problems that are difficult to get over. This is why wigs with regard to African American Human Hair Wigs girls will be more common than ever.

Afro head of hair, or african american locks, since the hair is commonly referred to, has hair strands that are spring-like while unblemished Wigs For Women by simply chemical compounds. For that reason, the head of hair Wigs generally seems heavier Wigs and also denser compared to some other curly hair varieties. It is viewed as hairy and also heavy, bordering with that for being unkempt.
African American Hairpieces Certainly are a Style Declaration (StephenSer)
2017-04-08 02:59:07
A hairpiece can be an instant option for those Wigs
experiencing hair loss troubles. It's also the best way to get yourself appear distinct at a outfit get together. Hairpieces are really simple to receive and make use of and they're helpful at the same time. In the present instances, donning the wig may not be an embarrassing experience. Hairpieces have got progressed in ways Short Wigs
in an attempt to go well with your altering requirements involving people in recent times. Each synthetic as well as real hair hair pieces are usually popular among men and women of assorted ages.

Varieties of Dark Wigs

There are various forms of hairpieces available in the market, the actual African American hair pieces staying one among these people. Wigs can be found in diverse price tags Wigs
with regards to the product or service and its material. Manufactured Lace Front Wigs
fiber hairpieces are less expensive compared to human hair wigs because last option seems to be more sensible. Human hair hair pieces are really simple to sustain so because of this tend to be common.

Swarthy complexioned folks could go looking for Black wigs within hues which will go well with their particular Wigs For Women
skin tone. They are available in both darkish in addition to light hues. However, the most popular African American wig could be the Ebony hairpiece helping to make Dark females search stunning and beautiful. These kinds of hairpieces can be bought in an array of styles such as short, extended, fluorescent, curly, and also right. How big is the particular hairpiece is extremely important. You need to check out the wig cautiously prior to buying Cheap Wigs
to be able to make certain that no one otherwise offers put it on before you.
African American Wigs Certainly are a Fashion Declaration (StephenSer)
2017-04-12 02:58:23
The wig can be an fast solution for people Lace Front Wigs
experiencing hair thinning problems. It is usually a terrific way to become seem various in a halloween costume celebration. Wigs are really easy to get and employ and they are useful too. In the present occasions, sporting any wig is not very an upsetting encounter. Hair pieces have progressed you might say Wigs
so as to match your altering requires involving people through the years. Equally synthetic and also real human hair hair pieces are usually well-liked by women and men of varied ages.

Forms of African American Wigs

There are various kinds of wigs available for sale, your African American hair pieces being one of these people. Hairpieces can be purchased in different price tags Wigs
depending on the product and its particular material. Artificial Wigs For Sale
fiber wigs be cheaper when compared with natural splendor wigs because last option seems to be much more sensible. Real human hair wigs are really simple to keep and hence tend to be more popular.

Swarthy complexioned folks might have to go looking African American hair pieces in colors that will fit his or her Real Hair Wigs
skin. They come in each darkish in addition to lighter shades. However, the most used African American hairpiece will be the Ebony wig helping to make Black females look spectacular and gorgeous. These types of wigs can be purchased in a wide range of variations such as brief, extended, fluorescent, curly, and direct. The dimensions of the wig is important. You have to check out the wig cautiously prior to buying Wigs For Black Women
to help you make sure that no body else offers worn it prior to you.

コメントを投稿

関連するみんなの記事