g**********s
发帖数: 856 | 1 假设一女体重140lb，bf 25%，那按你的公式
protein = 140(1-0.25) = 105g
calories = 140(1-0.25) = 210 cal
carb = 140(1-0.25) = 210g
要是我没算错，这个太荒唐
一般维持体重差不多每天1600 calories; protein 30g; carb类 fiber 30g, sugar
20g
减脂 = cut糖，增加纤维，增加蛋白质
增肌 = 全部增加 |
|
s********r
发帖数: 348 | 2 能help一下么？我发现正常吃永远都是carb最高，protein一般20%，但是atkins的protein要提
高到什么程度？ |
|
|
g******n
发帖数: 53185 | 4 今天我开车的时候也听电台说这个研究了，基本意思就是根据20年左右的数据，50岁到
65岁的人如果多吃牛肉鸡蛋等high protein的食物，更容易得癌症和糖尿病等疾病。
超过65岁的老年人因为吃得少体重丢失比较快，反而应该多吃一些牛肉鸡蛋等high
protein，可以减少癌症发病率。 |
|
m********9
发帖数: 6 | 5 More protein, less fat, convenient, isn't it better protein resource than
meat? |
|
a**********0
发帖数: 87 | 6 Better not to take high dose protein suppliments. We do FireFighter annual
physicals, 1 out of 5 has proteinuria, this is due to the renal damage from
long-term high-dose protein (powder) intake when they were young, ussually
during body building.
Ask your own PCP, if they are well-informed, they will tell you the same
thing. |
|
t********y
发帖数: 749 | 7 我算了一下， 我一个月要吃至少50个。 平均一天差不多要2个protein bar。。。。饿
了就吃protein bar 。 正餐倒不好好吃了。 |
|
a***c
发帖数: 578 | 8 不吃，只吃real food
我算了一下， 我一个月要吃至少50个。 平均一天差不多要2个protein bar。。。。饿
了就吃protein bar 。 正餐倒不好好吃了。
★ Sent from iPhone App: iReader Mitbbs Lite 7.56 |
|
|
c*****t
发帖数: 1879 | 10 The solubility of protein depend on several factors, listed
in term of importance.
1. The protein itself.
2. pH.
3. Temperature.
4. Salt.
5. Buffer. |
|
M****e
发帖数: 70 | 11 is there IP assay available? i think it is necessary if you
can fractionate the protein by columns (many biochemcal stuffs
that i am not familiar, which i read from purification of
p300 transcription factor, i think people in this area knows
a lot). then do the assay to see which fraction has the
activity (is this specific reaction?) thus you know the effective
size.
is this endogenous or expressed protein? guess it is
endogenous, given the big size. try IP with the antibody and
do the assay. or |
|
s*******e
发帖数: 23 | 12 for proteins like to stick in inclusion bodies, I strongly recomment
my protocol (in fact, from a literature I can't find the place leh)
http://www.sit.wisc.edu/~sguang/protocols/index.html
The last one is "using Sarkosyl to purify GST fused proteins"
u can try it. |
|
t********m
发帖数: 2 | 13 I had the same problem once. No good way to improve it. Two pieces of
suggestion:
First, try different amount of thrombin, different incubation time and
different temperature.
Second, try different enzyme.
My problem was solved by adding a TEV cleavage site between the GST and my
target protein. TEV is a very sequence specific protease. My protein was
purified by glutathione column and eluted with TEV enzyme. It worked. |
|
m**o
发帖数: 13 | 14 It looks the sepecificity of subcellular localization was modified. Did you
make any change to the N terminal of the protein? One possibility is the
specific signal pepetides at the N terminal has been modified that led to
the changes of its subcellular localization. Even the tag sequence may make
some changes. Well, sometime, in some case, the modification of subcellular
location may be seen from an overexpression cell line, that's possibly caused
by diffusion of either protein location or det |
|
E**********y
发帖数: 991 | 15 请做过相关实验的牛人推荐一个exclusive mitochondrial matrix protein。觉得很多
传统的
matrix protein其实都不只在matrix有像HSP60之类。
谢谢 |
|
d********r
发帖数: 303 | 16 regular protein crystallography is kind of mature area and there are lots of
crystallographers already. So be careful as there may be of limited career
opportunity.
you may try your luck in membrane proteins. however, the risk is quite high
in this area. |
|
m******m
发帖数: 13 | 17 A postdoctoral research position funded by a four-year NIH grant is
immediately available in Dr. Jianlin Cheng's group in the Department of
Computer Science and Informatics Institute at the University of Missouri,
Columbia. The scientist at this position will work on a project to design,
develop, and benchmark cutting-edge computational methods and tools to
predict protein structures from protein sequences. The methods and tools
will be tested in the biannual world wide Critical Assessment of Te |
|
w******e
发帖数: 1187 | 18 有没有什么宝典推荐阅读？
我要做的实验，希望能conjugate a few ug protein to beads (dynabeads, etc)。
要求是用量越少越好（protein贵啊～），在此前提下beads coverage越高越好，
有什么product可以推荐？conjugation完成后如何定量？lab里用nanoorange，据说
效果很一般。
最后，lab用NHS-EDC link primary amine，有什么alternative吗？我指link蛋白
上其他位点。
非常感谢！ |
|
|
H*g
发帖数: 2333 | 20 I am wondering if we could observe protein monomers form a trimer
formaiton from crystal data, does it indicate such protein monomer could
interact with itself and form a trimer in vivo? Thanks! |
|
H*****e
发帖数: 120 | 21 Everytime, it is amazing to see the 3-D binding model for small molecule
binding a protein. Now I found a small molecule (a boring one!) binding a
protein (with known crystal structure). For publication purpose, I am very
interested in try to have such a model because I noticed such a computation
based modeling is publishable. Although I am not a structure person, I was
told that it can be done by computation based prediction in a seminar. I
tried google but found too many and too confusing. |
|
s******y
发帖数: 28562 | 22 Most likely is protein aggregation
Did you run a control with protein alone? |
|
a****o
发帖数: 1786 | 23 One extra lane will tell you if your aptamer bind to BSA. This is kind of
necessary control. you need to show ur aptamer not bind to any unrelated
proteins.
you can try 0.5x TBE, lower concentrration of acrylamide, I usually use 6%.
I tried 4% before, it is not a big deal.
silicate only one plate, it is very easy to separate your gel from that
plate, but stick to the other plate. put one a piece of DE filter will
transfer the whole gel to filter.
Good luck.
I suspect the protein gel system will |
|
g********4
发帖数: 4959 | 24 题目很误导人啊。我以为是问protein engineering问题的，其实问的是cloning问题。
实际上，chimera protein除了常见的GUS，GFP， LUC之外，其它蛋白fusion 表达成有
功能的还是蛮难的。 |
|
c******r
发帖数: 3778 | 25 如果只是为了跑western，sonicate足够了。
你load了多少protein？sonicate多大的volume？在1.5ml管子里还是15ml管子？多长时
间？多少次？
要根据体积选用不同的头。如果体积太大，sonicate效果不好。如果体积太小，
sonicate很容易起泡泡。一旦起泡泡sonicate就没用了。
一般sonicate之后弹一下管子，以不粘稠可以自由流动为准。否则就再sonicate 20秒。
之后像ls说的，离心max speed 5min，取上清，95度10分钟，冷却，上样。
是很
protein |
|
t*d
发帖数: 1290 | 26 But the definition of a 'real' interaction depends on the context. “Does a
real interaction mean that two proteins interact if they are placed next to
each other in a test tube, or that they must interact in a cell? Or does
real mean that the interaction should have a biological function?” asks
Ideker. |
|
K******S
发帖数: 10109 | 27 和这个领域沾边的看题目都能猜到是科罗拉多那个组的。很有意思，做PROTEIN ARRAY
里算是挺好的
了。不过800多PROTEIN和总的PROTEOME比起来还只是一小部分。而且他们用体外表达，
并不是所有
的蛋白能正确FOLD和有酶活性 |
|
f*****s
发帖数: 104 | 28 最近用GE healthcare的glutathione sepharose 4B resin purify a couple of GST-
tagged transcription factor DNA binding domains. The protein were bound to
the beads with high efficiency. However, when I used glutathione buffer to
elute the GST-protein off the beads, they can't be eluted. I tried 10 mM ,50
mM and 100 mM glutathione. To make the buffer, I diluted 1 M Tris (pH 7.5
at room temperature) to 50 mM, and added glutathione powder. There was also
2 mM DTT in the buffer. The elution was carried out... 阅读全帖 |
|
c*********r
发帖数: 1312 | 29 我想我明白了你说的crosslink和我说的crosslink不是一个东东。。。
我说的是把抗体和beads上的protein A/G交联起来，你可能是指把IP complex里的所有
protein crosslink吧。
不知道我说的对不对。^_^ |
|
w********e
发帖数: 275 | 30 I'm not familiar with protein mass spec,I'd appreciate some help for a
question.
The protein samples was digested by trypsin, which cuts after K and R. But
why some peptide fragments follow amino acids other than K and R in the
result file? and the same fragment appears more then once. are those
fragments real?
Thanks a lot! |
|
c*********r
发帖数: 1312 | 31 好像Qiagen的RNA提取的试剂盒就可以，隐约记得说明书上有说把RNA binding之后的溶
液可以留着做蛋白提取。
Appendix F: Acetone Precipitation of Protein from Buffer RLT Lysates 72
http://www.google.com/url?sa=t&source=web&cd=1&sqi=2&ved=0CBMQF
不过“The precipitated, denatured protein is suitable for applications such
as SDS-PAGE, western blotting, and 2D gel electrophoresis.”不知道是否时候MS
。但PAGE之后还是可以MS的吧。 |
|
A******y
发帖数: 2041 | 32 How do you know is post-translation? Did you see different bands with
different molecular weight with your antibody? Are you sure your antibody
is binding to the right protein? There are translational control and
control of mRNA splicing. Some proteins can bind to your mRNA in cell A and
stop translation. Your primers for RT-PCR just amplifying a small fragment
, maybe you are missing alternative splicing. There are so many
possibilities.
Not everything go though proteasome either but good... 阅读全帖 |
|
s****l
发帖数: 395 | 33 关键看研究啥问题吧，很多人用overexpress的system找protein-protein interaction
，也发了cell的 |
|
x*******i
发帖数: 32 | 34 Hello there:
Trytophan fluorescence spectroscopy could be used to analyze whether protein
is compact or open. Ex at 288 nm and em around 320 nm suggests that protein
is compact (trytophan in hydrophobic environment). Em at longer wavelength
suggests an open structure. Also relative fluorescence intensity could tell
something? Anybody know why?
Thanks |
|
x*******i
发帖数: 32 | 35 Thanks! But why the philic environment causes emission red shift?
Bascially we have a protein soluble at room temperature but it precipitates
at cold temperature such as 4 degree. It re-dissolves when temperature
increases. I am thinking about fluorescence spectroscopy to see compactness
or openness of protein with temperature. |
|
e**s
发帖数: 856 | 36 actually, 10%-12% is fine. Stacking gel is always better.
When I run 400kd protein, I use precast gel. If you have precast gel, it is
good for any protein |
|
c*******4
发帖数: 41 | 37 Does anyone know how to measure the concentration of protein that is bound
to lipid membrane? I can not measure it by UV/Vis because the phospholipid
greatly interferences the UV/Vis absorbance at very wide range.
I found a paper that used densitometry with a software (ImageQuant) to
determine the membrane bound protein concentration. Does anyone know how
reliable it would be. Many thanks!!! |
|
s********n
发帖数: 2939 | 38 对Protein therapeutics很感兴趣，但不是做这行的，想了解一下Protein
therapeutics的target有哪些，存在哪些问题？如果有reviews推荐就更好了。
本人的了解程度仅限于antibodies和insulin，EPO等。
望不吝赐教。 |
|
n***w
发帖数: 2405 | 39 Because most of my protein is in inclusion bodies and I don't wanna directly
go to the last resort dissolving
with guanidine hydrochloride, I found a protocol using this detergent to
increase the production of soluble
protein.
I know nothing about its physical chemical properties and I haven't thought
about the impact of this
ingredient.
Thanks. |
|
a*******u
发帖数: 19 | 40 GST-fused protein A 拉下了B,C,D.且ABCD在胞浆和核内都有分布。文献报道BC、BD在
胞浆和核内都有直接的相互作用，但BCD是否在一个复合物未知或未报道。现在猜想
ABCD很有可能在一个复合物，A作为一个scaffold protein的角色。有什么方法说明4个
蛋白或者至少3个蛋白形成一个complex？有没有比较简单点的方法，国内实验室的设备
条件比较限制。 |
|
a**y
发帖数: 464 | 41 no problem. Protein G is a very stable protein, that is why it has been widely used for affinity purification.
ip |
|
b**********8
发帖数: 349 | 42 最近做ChIP,按照Upstate公司Chromatin Immunoprecipitation (ChIP) Assay Kit（
Cat No.17-295）的protocol，需要用到protein A Agarose/ Salmon sperm DNA，每个
reaction先后需要75和60ul,我每次买的那种只有2.5ml的规格， (Cat.# 16-157) 需要
300多刀，大概只能做两次ChIP,感觉用的太快了，好浪费。有人用过这个么？有没有可
能减半量使用？另外，Salmon Sperm DNA /Protein A Agarose-50% Slurry
是什么意思？ |
|
q****2
发帖数: 208 | 43 按我得经验 减半没啥问题 或者你可以单独再去买Salmon Sperm DNA /Protein A
Agarose beads。
Salmon Sperm DNA /Protein A Agarose-50% Slurry就是50％的beads 50％ buffer（
其中包含了一定浓度的Salmon Sperm DNA） |
|
l****y
发帖数: 398 | 44 sorry to be negative.
But it seems anything based on affinity purification-MS won't work.
As far as i know, people have tried all sorts of tricks (crosslinking,
minichromatin,targeted cleavage, silac)and failed.
The nonspecific background is ridiculous. It is like every protein is there.
Of course, sometimes a lucky person can pick out one interesting protein by
sharp instinct. but in general, it fails.
if you can make it work as well as CHIP,you get a career. |
|
s******s
发帖数: 13035 | 45 说实话，那个PICH我还没有全部理解。
理论上，sonicate以后，不被protein protect的DNA应该断掉了，
但是杂交的时候，被protein crosslink的部分应该不容易杂上吧？
是不是和前面有人说的telomere的所谓特殊结构有关系?
year
and |
|
g*********3
发帖数: 177 | 46 关于DNA-protein complex的
一般的策略是crosslink---nuclei isolation---Sonication---IP
实验室的师兄说crosslink后细胞比较像jelly，isolation的效率可能不好。建议可以
先cell lysis/nuclei isolation---crosslink，这样可能会损失一些DNA-Protein
complex，大家有见过第二种方法吗？可否给个链接，谢谢。另外，第一种isolation的
效率怎样。
谢谢各位。 |
|
|
f**********e
发帖数: 1994 | 48 用 rasmol 打开，用 restrict 指令选 chain id
protein |
|
W*********e
发帖数: 247 | 49 pymol里选chain id
或者用记事本打开pdb每个蛋白单独存成一个pdb
protein |
|
K**4
发帖数: 1015 | 50 很难说，大多数的protein都是multi－domain的
而这个问题对于不同物种可能也答案不同
那些进化位置很早的物种，可能蛋白组成上会简单些
所以总的来说，估计有70－80％是multi－domain的吧
如果基于计算的结果，基于pfam中的数据肯定是underestimate的 |
|
