s******n
发帖数: 110 | 1 p*********[email protected]
请用这个邮箱和Dr.He联系。我用过他们公司合成的peptide，很好！我们这儿（加州大
学）几个实验室都用他们公司合成peptide。 |
|
K******S
发帖数: 10109 | 2 depends on the length of the peptide, if it's short, any facility/core with
peptide synthesis can do it. |
|
c******a
发帖数: 267 | 3 peptide 2.0不贵，质量还靠得住
另外可以支持一下同胞的公司，genscript，他们也做peptide, 应该也没问题 |
|
D***a
发帖数: 516 | 4 这两天突然对Cell Penetrating Peptide产生了兴趣，看了一点综述，了解了Tat等多
肽序列可以将蛋白递送到细胞内。由此想到丁胜的蛋白诱导iPS，看了一下那篇文章，
的确也用了这个方法。
版上多次提及丁胜的这片文章不可信，那么疑点是在哪里？是Cell Penetrating
Peptide的效率不高，还是其他问题？谢谢。 |
|
h******n
发帖数: 221 | 5 10几个氨基酸的peptide能自由进入细胞吗？或则有什么方法让这样的peptide进入活细
胞 |
|
v**********t
发帖数: 9 | 6 最近从某公司订了synthesized peptide，但是似乎不纯。
请问如何确定50aa左右的peptide的纯度？
谢谢!! |
|
n*********y
发帖数: 54 | 7 多谢大家的回复。MMP是N-methylmorpholine。我试过了3小时和16小时脱保护，结果没
有太大区别。经过重新分析质谱结果，我相信多出的分子量49（之前以为是50）是由于
有一个piperidine adduct（＋67）和一个aspartimide（－18）的结果。只是仍不清楚
到底是哪两个Asp的side chain发生了副反应。我查到两篇报导化学合成flag peptide
的文献，都是用fmoc化学固相合成的。一篇用的试剂和我用的大同小异，不过是手工合
成的。难道手工合成可以避免aspartimide的生成？我已经用很短的时间脱fmoc了。（
2X2min）
最后一招就是用Boc化学合成了，如果实在没有别的办法的话。
有人用fmoc化学作成过flag peptide吗？ |
|
T****O
发帖数: 407 | 8 1. Make it all d-AA with the reversed sequence, a.k.a., Retro-Inverso
2. Whoever saying cyclization can prevent degradation is ... anyway. It's
easy to try and not expensive.
3. Peptoids are very different. Don't branch out too much.
Finally, are you sure your peptides were broken down by enzymes in vivo?
How did you analyze or track peptides in vivo? |
|
A******y
发帖数: 2041 | 9 I assume you are going to make the peptide on resin. You can buy glutamic
acid resin conjugated to the resin for head to tail ligation. Your sequence
should be okay, but remember that longer you make it, the harder it will be.
Do not add proline to the sequence, the solid phase synthesis hates proline
and you will likely to fail the elongation after the proline residue.
However, if you like challenge, feel free to do so. The final cycolization
could be tricky, too. You might not be able to... 阅读全帖 |
|
k*****i
发帖数: 314 | 10 Anybody has some experience on industry peptide synthesis?
I would like to know what will be a normal price for buying a cyclic peptide
(with disulfide bond). The fomular will be (XC-XXXXXXXC-X)
Thanks a lot |
|
|
s*****d
发帖数: 110 | 12 小弟最近在做个实验， 希望能有尽量高的peptide mapping coverage， 但是有几个
peptide做了几遍都看不见， 有什么方法或者调什么parameter可以把它搞出来啊？
我用的是trypsin digestion， dionex 3000+ LTQ
希望大家帮帮忙啊 多谢！！ |
|
c*****t
发帖数: 198 | 13 有影响因子的就好，至少10个包子以上，影响因子越高，包子越多。多谢。请站内信箱
联系。
lp催的急，添加一些个人资料：我有文章8篇 (IF 2.3-25.9)，其中一二作5篇(IF 4.8-
12.9, Nano Letters, PNAS, Nature Communications, Structure, JCPC)。
Structure, protein, peptide, chemical biology, medicinal chemistry，实验的，
计算的，都行。 |
|
c*****t
发帖数: 198 | 14 Structure, protein, peptide, bioinformatics，MD simulation, chemical biology
, medicinal chemistry，实验的，计算的，都行。
为JACS, Biochemistry, PLOS ONE 和 European Biophysics Journal审过稿。
请站内信箱联系，我将把CV寄给您。 |
|
c****i
发帖数: 40 | 15 Impact factor: 6.567
关键词: peptide，hydrogel, drug delivery, drug release
需要有研究过高分子水凝胶及药物释放的reviewer
站内邮件联系，麻烦给我你的名字，email邮箱, research background, instrument
expertise。我会foward给editor的。 |
|
c****i
发帖数: 40 | 16 Impact factor: 3.485
关键词: peptide, regenerative medicine, signaling ability, cartilage
regeneration
需要有研究过biopolymer for tissue regeneration 的reviewer
站内邮件联系，麻烦给我你的名字，email邮箱, research background, instrument
expertise。我会foward给editor的。 |
|
A***l
发帖数: 302 | 17 5. A typical example: Search for synthetic peptide HIV-1 vaccine
Around the world, millions of people are suffering from AIDS and hundred
of thousands of people die every year because of it. In most cases, the
causative agent is human immunodeficiency virus-1(HIV-1), which leads to
lysis of helper T cells. But vaccination is made difficult by the
antigenic diversity of HIV strains. HIV constantly changes its coat proteins
to evade detection by the host. Indeed, the mutation rate of HIV is 65
tim |
|
G***G
发帖数: 16778 | 18 I have ms1 data. no ms2.
can I do peptide identification using the ms level 1 data?
if I can, which tool should I use?
Thank you. |
|
K******S
发帖数: 10109 | 19 just take a minute to think about it, how is peptide identification achieved
? |
|
c*****e
发帖数: 436 | 20 have to do long experiments with temperature ramping from -10C to 45C and
the whole experiments last for 2 weeks, on peptide in solution sample.
question: does this sample has to be prepared with sterilization?
Thanks!!!
Baozi will be given to helpful replies!!! |
|
m**z
发帖数: 787 | 21 i guess it really depends on how stable the peptide is... This is just like
proteins. I know proteins to be stable at 40C for days, other proteins can
only last for several hours. varying the solution conditions may help, but
this has to be tested...
I don't think sterilization is that important. Sterilization by a 0.2uM
filter is also easy to do though. But you may lose some sample during
fitration. |
|
c*****e
发帖数: 436 | 22 how to do sterilization, it seem every step has to be under a hood or
something? I've no knowledge of these stuff at all because I'm not biology
major.
my peptide is (Val-Pro-Gly-Val-Gly)3 lyophilized powder. Previously I just
add distilled water into it. And I use this sample at body temperature for
month. Does this mean all my work are garbage now?
like |
|
w******e
发帖数: 1187 | 23 比如RGD peptide derivative能coat到ELISA plate上做capturing agent吗？
多谢！ |
|
a*****a
发帖数: 640 | 24 没保障，如果你要测针对这个蛋白的抗体IgG，2a，E基本上peptide上表位很有限
为什么不用全蛋白？
如果你要测针对这段肽的，那就要用这个肽而不是全蛋白 |
|
w******e
发帖数: 1187 | 25 my aptamer works for detection for sure. I just don't know whether my
peptide would stick or whether after stuck whether it still binds the
protein. anyway, it's just an intermediate idea not worth much time |
|
w******e
发帖数: 1187 | 26 en, covalent modification of peptides would be too messy, considering
that there is no controling which NH2 would be linked.
I might try that w/ aptamer w/ terminal NH2 some time later hehe |
|
c*****o
发帖数: 18 | 27 Hi folks,
I try to purify a peptide(AMP) from the bacteria broth culture. It looks
like that so much sugar from the broth tightly bound with the protein even
after HPLC and centricon pufication. I still find the dark sugar color in
the active fraction. and this is a big problem for the later SDS-PAGE
running since suger blocks the gel pore, I can not get a band......always
smear. Does somebody have experience to romove suger?
thanks for your time and help. |
|
t***i
发帖数: 204 | 28 我有一个老鼠基因，我怀疑可能是peptide precursor。怎样是最好的办法来验证？ |
|
G***G
发帖数: 16778 | 29 can anyone explain a little bit about how to get
peptide's intensity from MS/MS?
or give a reference to it?
thanks. |
|
y*****w
发帖数: 146 | 30 peptide在ER内被修饰，然后如何被导入mitochondrial呢？或者导入到细胞质也行，只
要不被降解或者分泌处体外。有这种可能行吗？需要加什么信号肽呢？ |
|
h*******o
发帖数: 4884 | 31 常用的方法是加一个mitochondrial targeting signal peptide.
具体的序列应该可以google出来 |
|
l***y
发帖数: 4671 | 32 是不是可以用某个可以妨碍 protein elongation or folding 的 peptide analog？ |
|
y***i
发帖数: 11639 | 33 我猜会。我都是放在signal peptide后面。 |
|
y***i
发帖数: 11639 | 34 我猜会。我都是放在signal peptide后面。 |
|
h**********r
发帖数: 671 | 35 很可能会影响功能吧，我只看过原核的paper,有的signal peptide带的电荷挺重要的。 |
|
w****s
发帖数: 235 | 36 大家都用什么cross linker to cross link peptide for antibody purification?
NHS agorase beads 好用么？ |
|
w****s
发帖数: 235 | 37 I'm having a problem to yield sufficient antibody (rab polyclonal)from
the
1st serum bleed (~6ml serum).. 总共得到了100 ug.. but based on the ELISA,
the antibody
tilter is pretty high ~100k; my intuition is that I should get much
more. so I guess either I did not X- link well
the
peptide/antigen( should check with MS though) or simply low yield is
expected for 1st bleed?
有谁做过/有经验么？ 谢谢。 |
|
y******8
发帖数: 1764 | 38 Live fluorescent imaging of short peptide with subcellular resolution. This
would be the method of the year if you can make it routinely working.
Radioactive labeling might be the cheapest universal method to try. Other
alternatives are very expensive. |
|
b******y
发帖数: 627 | 39 Biotin-SA-Fluorophore is a good choice, in case you missed my previous
suggestion: i.e. biotinylated your peptide and used fluorophore labeled
Straptavdin to detect, both of which should be easy to get. |
|
a*****a
发帖数: 46 | 40 in vivo里面的peptide有多大的role? |
|
O*C
发帖数: 649 | 41 不懂啊，请问大牛怎么in vivo sequencing peptide？ |
|
m******p
发帖数: 67 | 42 Need to make a recombinant protein. If the signal peptide should be included
if to express it in E coli or in mammalian cells?
thanks. |
|
s******s
发帖数: 13035 | 43 如果我在signal peptide的N端多加一个proline, 会影响translocation和cleavage么？ |
|
|
e****e
发帖数: 1042 | 45 就大小不一样呗！我要的产物是3kD左右的peptide，其它的都是杂质，我想知道比如大
于10kD的protein的量是多少，就算是protein的杂质量。我不需要分离它们。 |
|
e****e
发帖数: 1042 | 46 Thanks for your suggestion! But we currently already use HPLC to quantify
our peptide product. Protein cannot be quantified by FPLC\HPLC, right? I'm
not sure about Mass spec though. |
|
s******y
发帖数: 28562 | 47 咦？ 有何不可呀？你这个问题的实际就是要把蛋白和小肽分开，所以HPLC/HPLC
是最简单也最经典的方法（我猜你是学化学的？所以没有这么做过？）
用个比较小的resin，比方说Sephedex G-10, 几乎所有蛋白都在dead volume 里面
（就是第一个峰）流出来了。然后后面的峰就是peptide 了。要定量的话太简单了，
最直接的就是看OD280 和 OD230， 要更精确的话就把管子里的东西一一拿去测
bradford,
甚至你要上碳定量或者氮定量都行。
Mass Spec 对于小量的污染很敏感，可以用来检测残留物，但是定量性不好。 |
|
n********k
发帖数: 2818 | 48 hi, buddy, what define a protein or peptide, is it the size? 50-100aa?
have
domains) |
|
n********k
发帖数: 2818 | 49 BTW, are there anyway or people detecting the shorting ORF by looking for
peptides? |
|
n********k
发帖数: 2818 | 50 but I was thinking about determining the existence of peptide and then
reverse to find potential ORF...feasible or not, any potential/progress in
this area
of
However,
a |
|
