Redian新闻
>
谁知道适度抑制呼吸链的哪个环节可以升高线粒体膜的势能?
avatar
谁知道适度抑制呼吸链的哪个环节可以升高线粒体膜的势能?# Biology - 生物学
T*y
1
RT
avatar
s*y
2
在我的理解中,抑制 F1Fo-ATPase 是可以短时间内升高势能的。
但是在正常细胞中,会通过其他方式(比方说打开某些通道,以及抑制呼吸链)来降低
势能。
所以如果你需要长时间的升高的话可能需要其他抑制剂一起用

【在 T******y 的大作中提到】
: RT
avatar
T*y
3
谢谢Sunnyday!
能告诉几种好用的F1Fo-ATPase 抑制剂吗?另外抑制F1Fo-ATPase会产生ROS(Reactive
oxygen species )吗? 如果升高4到6小时的话,需要和其他抑制剂合用吗?如果需
要,那些抑制剂比较合适?
avatar
h*o
4
4 to 6 hours of Complex V inhibition will most likely lead to collapse of
mitochondrial membrance potential.
Inhibition of ATP synthase should only induce a transient increase in
membrane potential.
You can try oligomycin/astracylocide as ATP synthase inhibitor

Reactive

【在 T******y 的大作中提到】
: 谢谢Sunnyday!
: 能告诉几种好用的F1Fo-ATPase 抑制剂吗?另外抑制F1Fo-ATPase会产生ROS(Reactive
: oxygen species )吗? 如果升高4到6小时的话,需要和其他抑制剂合用吗?如果需
: 要,那些抑制剂比较合适?

avatar
T*y
5
Hellozero,
Do you know some other targets that the inhibition of them could cause
mitochondrial membrance potential incresed for longer time? Thanks!
Tankcity
avatar
h*o
6
There is no ETC/OXPHOS inhibitor that, at least from what I know, can induce
long-term hyperpolarization of mitochondrial membrane.
And sustained mitochondrial hyperpolarization is not necessarily a good
thing, usually associated with increased oxidative stress.

【在 T******y 的大作中提到】
: Hellozero,
: Do you know some other targets that the inhibition of them could cause
: mitochondrial membrance potential incresed for longer time? Thanks!
: Tankcity

avatar
j*b
7
How do u know hyper polarization increases oxidative stress?
What is the mechanism?
For LZ, you can try different conc. oligomycin

induce

【在 h*******o 的大作中提到】
: There is no ETC/OXPHOS inhibitor that, at least from what I know, can induce
: long-term hyperpolarization of mitochondrial membrane.
: And sustained mitochondrial hyperpolarization is not necessarily a good
: thing, usually associated with increased oxidative stress.

avatar
g*4
8
You can try nigericin.
avatar
s*y
9

在正常情况下面应该都是这样的吧?一般而言(不包括特殊情况),hyper
polarization表明被呼吸链放到mitochondira外面的电子不能正常的通过F0-F1-ATPase
流回mitochondria。那些自由电子最终就会和外面的水反应而产生ROS

【在 j*b 的大作中提到】
: How do u know hyper polarization increases oxidative stress?
: What is the mechanism?
: For LZ, you can try different conc. oligomycin
:
: induce

avatar
j*b
10
“那些自由电子最终就会和外面的水反应而产生ROS”
这个有参考文献吗?

ATPase

【在 s******y 的大作中提到】
:
: 在正常情况下面应该都是这样的吧?一般而言(不包括特殊情况),hyper
: polarization表明被呼吸链放到mitochondira外面的电子不能正常的通过F0-F1-ATPase
: 流回mitochondria。那些自由电子最终就会和外面的水反应而产生ROS

avatar
s*y
11
非常抱歉,我查了一下资料发现我把位置说反了。那些多余的电子是在mitochondria
内部,不是在外部。
Hyperpolarization 导致increased oxidation 的大致机理是:
http://circ.ahajournals.org/content/117/19/2431.full
In coupled mitochondria, in the presence of excess calories and low
cytoplasmic ADP (due to less exercise), complex V stops bringing H+ back in
the matrix and thus ΔΨm increases; eventually the very negative potential
prevents further H+ pumping and the ETC is stalled. As electrons keep coming
in, they cannot be oxidized and interact with molecular O2, increasing ROS
production.

【在 j*b 的大作中提到】
: “那些自由电子最终就会和外面的水反应而产生ROS”
: 这个有参考文献吗?
:
: ATPase

avatar
T*y
12
Thank all of you. These information are very useful for me.
avatar
h*o
13
hyperpolarization eventually lead to inhibition of the ETC, which induces
oxidative stress by multiple mechanisms.
Oligomycin will not induce "sustained hyperpolarization".
Actually, I don't think any ETC inhibitor will induce sustained
hyperpolarization.
Usually, a collapse of membrane potential will happen after "maybe 30 mins
or even shorter" of OXPHOS inhibition.

【在 j*b 的大作中提到】
: How do u know hyper polarization increases oxidative stress?
: What is the mechanism?
: For LZ, you can try different conc. oligomycin
:
: induce

avatar
j*b
14
谢谢
因为准确测量ROS很困难,所以目前这些东西还只是假说
For example, electrons keep coming in and react with o2,
If etc is stopped by high H+,I think electron generation will be also
greatly decreased.

in
potential
coming
ROS

【在 s******y 的大作中提到】
: 非常抱歉,我查了一下资料发现我把位置说反了。那些多余的电子是在mitochondria
: 内部,不是在外部。
: Hyperpolarization 导致increased oxidation 的大致机理是:
: http://circ.ahajournals.org/content/117/19/2431.full
: In coupled mitochondria, in the presence of excess calories and low
: cytoplasmic ADP (due to less exercise), complex V stops bringing H+ back in
: the matrix and thus ΔΨm increases; eventually the very negative potential
: prevents further H+ pumping and the ETC is stalled. As electrons keep coming
: in, they cannot be oxidized and interact with molecular O2, increasing ROS
: production.

avatar
j*b
15
Thanks for the reply.
Can I have the reference that oligomycin will not induce sustained
hyperpolarization.

【在 h*******o 的大作中提到】
: hyperpolarization eventually lead to inhibition of the ETC, which induces
: oxidative stress by multiple mechanisms.
: Oligomycin will not induce "sustained hyperpolarization".
: Actually, I don't think any ETC inhibitor will induce sustained
: hyperpolarization.
: Usually, a collapse of membrane potential will happen after "maybe 30 mins
: or even shorter" of OXPHOS inhibition.

avatar
h*o
16
I don't have any references at hand.
But look for any paper that do oligomycin treatment with TMRM measurement.
Usually the assay won't last over 30 minutes and the initial rise in
membrane potential usually will be gone around 20 minutes, unless a very low
oligomycin dose is used then the hyperpolarization won't be significant.

【在 j*b 的大作中提到】
: Thanks for the reply.
: Can I have the reference that oligomycin will not induce sustained
: hyperpolarization.

avatar
l*y
17
。。。电子是还原性的吧?咋能变氧化性的 ROS 了?

【在 s******y 的大作中提到】
: 非常抱歉,我查了一下资料发现我把位置说反了。那些多余的电子是在mitochondria
: 内部,不是在外部。
: Hyperpolarization 导致increased oxidation 的大致机理是:
: http://circ.ahajournals.org/content/117/19/2431.full
: In coupled mitochondria, in the presence of excess calories and low
: cytoplasmic ADP (due to less exercise), complex V stops bringing H+ back in
: the matrix and thus ΔΨm increases; eventually the very negative potential
: prevents further H+ pumping and the ETC is stalled. As electrons keep coming
: in, they cannot be oxidized and interact with molecular O2, increasing ROS
: production.

avatar
s*y
18
活性和还原性是两个不同的概念啊。
纯氧分子虽然理论上是强氧化剂,但是不被激活的话就不是那么容易起作用。
电子如果和氧分子起反应之后就会接着和水起反应,最后产生H2O2.

【在 l***y 的大作中提到】
: 。。。电子是还原性的吧?咋能变氧化性的 ROS 了?
avatar
l*y
19
查了一下,的确如此。电子把氧分子变成了自由基形式的 superoxide。所以是从热力
学上看是把氧分子还原成 H2O2,
O2 + 2H+ + 2e -> H2O2
从动力学上看是通过自由基活化来降低反应能垒。
O2 + e -> O2-
O2- + 2H+ + e -> H2O2
从生物学上看,是 SOD 对 O2- 解毒时不完全导致的:毕竟 O2- 的毒性比 H2O2 大得
多,所以最优先的任务是尽可能高效地消除 O2-,代价就是解毒不完全,毒性低的
H2O2 就交给下游机制去继续解毒了。
总反应是 2O2- + 2H+ -> O2 + H2O2
过程是 SOD 把一个电子从一个 O2- 转移到另一个 O2-,使得一个 O2- 被氧化成 O2,
另一个被还原成 H2O2。
O2- + SOD+ -> O2 + SOD
O2- + SOD + 2H+ -> H2O2 + SOD+

【在 s******y 的大作中提到】
: 活性和还原性是两个不同的概念啊。
: 纯氧分子虽然理论上是强氧化剂,但是不被激活的话就不是那么容易起作用。
: 电子如果和氧分子起反应之后就会接着和水起反应,最后产生H2O2.

avatar
h*o
21
Thanks for the reference.
As we can see, oligomycin induced slight hyperpolarization only last for 15-
20mins.

【在 r******g 的大作中提到】
: http://www.ncbi.nlm.nih.gov/pubmed/21486251
: Check out. Oligomycin temporarily hyperpolarizes mito.

avatar
h*o
22
H2O2 is not too bad.
The worst is actually NO +O2-
O2- is also bad but it is usually dismutated into H2O2.
So basically SOD reduce O2- into H2O2, which will be further reduced to H2O
by Peroxiredoxin, GSH, catalase, GPX,etc.

【在 l***y 的大作中提到】
: 查了一下,的确如此。电子把氧分子变成了自由基形式的 superoxide。所以是从热力
: 学上看是把氧分子还原成 H2O2,
: O2 + 2H+ + 2e -> H2O2
: 从动力学上看是通过自由基活化来降低反应能垒。
: O2 + e -> O2-
: O2- + 2H+ + e -> H2O2
: 从生物学上看,是 SOD 对 O2- 解毒时不完全导致的:毕竟 O2- 的毒性比 H2O2 大得
: 多,所以最优先的任务是尽可能高效地消除 O2-,代价就是解毒不完全,毒性低的
: H2O2 就交给下游机制去继续解毒了。
: 总反应是 2O2- + 2H+ -> O2 + H2O2

avatar
j*b
23
为什么持续不了? 內膜Leak

15-

【在 h*******o 的大作中提到】
: Thanks for the reference.
: As we can see, oligomycin induced slight hyperpolarization only last for 15-
: 20mins.

avatar
h*o
24
It is very complicated but we can consider the following factors that might
affect or contribute to the collapse of membrane potential after prolonged
inhibition of complex V.
1)H+ gradient eventually halt electron transport throughout the ETC.
2)Electron backflow cause ROS generation at complex I
3)Reverse ATP synthase activity to consume ATP to main membrane potential
which eventually lead to ATP depletion
4) There are backdoors on mitochondrial to allow partial uncoupling (UCPs,
FFA)

【在 j*b 的大作中提到】
: 为什么持续不了? 內膜Leak
:
: 15-

相关阅读
logo
联系我们隐私协议©2024 redian.news
Redian新闻
Redian.news刊载任何文章,不代表同意其说法或描述,仅为提供更多信息,也不构成任何建议。文章信息的合法性及真实性由其作者负责,与Redian.news及其运营公司无关。欢迎投稿,如发现稿件侵权,或作者不愿在本网发表文章,请版权拥有者通知本网处理。