PEG染色方法可以参考:
Kurfürst M. M. Detection and molecular weight determination of polyethylene glycol-modified hirudin by staining after sodium dodecyl sulfate-polyacrylamide gel electrophoresis[J]. Anal. Biochem. 1992, 200(2): 244–248
PEG染色方法可以参考:
Kurfürst M. M. Detection and molecular weight determination of polyethylene glycol-modified hirudin by staining after sodium dodecyl sulfate-polyacrylamide gel electrophoresis[J]. Anal. Biochem. 1992, 200(2): 244–248
我认为比较经典的文献的有
Introduction and overview of peptide and protein pegylation
PEGylation, successful approach to drug delivery
Beyond PEGylation
Peptide and protein PEGylation a review of problems and solutions
Chemistry for peptide and protein PEGylation
刚开始接触这行,看看这几篇就有整体了解和把握了作者: popo520 时间: 2013-4-18 12:49
推荐一本书
polyethylene glycol chemistry and biological application是J.M.harris编写1997年版
还有个更早的版本
Introduction and overview of peptide and protein pegylation
PEGylation, successful approach to drug delivery
Beyond PEGylation
Peptide and protein PEGylation a review of problems and solutions
Chemistry for peptide and protein PEGylation
刚开始接触这行,看看这几篇就有整体了解和把握了
推荐一本书
polyethylene glycol chemistry and biological application是J.M.harris编写1997年版
还有个更早的版本
Introduction and overview of peptide and protein pegylation
PEGylation, successful approach to drug delivery
Beyond PEGylation
Peptide and protein PEGylation a review of problems and solutions
Chemistry for peptide and protein PEGylation
刚开始接触这行,看看这几篇就有整体了解和把握了
Staining Procedure
After electrophoresis the gel was soaked in a 5% glu-
taraldehyde (Merck) solution for 15 min at room tem-
perature for fixation. Afterward the gel was stained for
PEG as follows. First, the gel was put in 20 ml of perchlo-
ric acid (0.1 M) for 15 min, and then 5 ml of a 5% barium
chloride solution (Riedel de Haen) and 2 ml of a 0.1 M
iodine solution (Merck, Titrisol 9910) were added ac-
cording to the procedure described by Skoog (3).
ANALYTICAL BIOCHRMISTRY 200,244-248 (1992)
上传不了整个文件,只能将PEG染色部分摘录,另外醛基修饰产生多修饰,你可以将修饰缓冲液pH降低作者: ququer787 时间: 2013-4-18 13:27
条件所限,可能只能用TNBS,查了下
ESTIMATION OF AMINO GROUPS USING TNBS
REFERENCE: Fields, R. 1972. Methods in Enzymology. 25:464-469.
MATERIALS:
Solution A: 100mls of 0.1M Na2SO3 (fresh each week)
Solution B: 1.0l of 0.1M NaH2PO4
Solution C: 1.0l of 0.1M Na2B4O7 in 0.1M NaOH (make up in acid and ddH2O- washed glass).
Trinitrobenzene sulfonate (TNBS) 10g in 10ml H2O, heat to dissolve and remove black flecks of oil by centrifugation. Add HCl to 2M and cool to room temp. Wash the crystalline precipitate on a glass filter with 1M HCl. Desiccate and store at 4oC in brown bottle. Make up to 1.1M fresh daily (100mg recrystallized TNBS in 0.2ml H2O).
METHOD:
1. make fresh daily Solution D: 1.5ml Solution A + 98.5ml Solution B
2. standard curve: BSA at 0.1, 0.2, 0.5, 1.0, and 2.0 mg/ml in 0.25ml H2O.
3. samples: same concentration range as above in same volume.
4. add 0.25ml solution C
5. add 10µl TNBS (take note of time!)
6. Incubate exactly 5 min at 23oC.
7. add 1ml solution D to stop reaction.
8. measure OD420. Standard curve should range from about 0.09 to >1.8
CALCULATION:
OD420 = 1.0 = 52nmol amino groups = 78nmol/1.5ml assay mix
"1.0mg/ml" BSA sample (0.25mg) = OD420 of 0.945 = 73.41nmol NH3
therefore, 0.25 mmol BSA = 73.41 nmol NH3 groups
67,000
3.73nmol BSA = 73.41 nmol NH3
therefore 1 molecule BSA = 19.8 molecules of lysine.
但是他的计算过程有点看不明白,他那个OD420 = 1.0 = 52nmol amino groups 是怎么算出来的,BSA包含60个赖氨酸,他算的1 molecule BSA = 19.8 molecules of lysine是什么意思作者: 不请自来 时间: 2013-4-18 13:32
关于TNBS等方法测定PEG修饰度可参考analytical biochemistry 254,254-262(1997);
comparison of results of various methods used to fetermine the extent of modification ofmethoxy polyethylene glycol 5000-modified bovine cupri-Zincsuperoxide dismute,
这篇文章对不同方法测定修饰度做了比较。计算也没有你的那麽复杂。
由于我只有复印文本,所以无法上传作者: jingling845 时间: 2013-4-18 13:33
呵呵,受益匪浅了。这些问题也是苦恼我的,ge的那个macro sp 实在是太贵了,用普通的sp纯化,peg修饰后蛋白载量降低的太多。定点的修饰倒好(其实所谓定点修饰,并不是完全依赖peg,有一句话,叫case by case,peg-ald是最早被成为定点修饰的,与N末端形成烷基键。其他的都基本是形成个酰胺健,如sc,nhs等等,其实对于这种peg,控制反应ph,使亲核位点质子化或去质子化,都可以使修饰位点的比例发生偏移,有几篇文献就是通过控制反应ph来达到获取同分异构体的目的,进而进行测定先灵的peg-intron就是冻干粉的,说明这个his上的酰胺健是容易水解的,反过来说就是容易被去质子化,低ph下即暴露出亲核位点。而lys的N原子则要高ph才能去质子化。)
这些问题也是苦恼我的,ge的那个macro sp 实在是太贵了,用普通的sp纯化,peg修饰后蛋白载量降低的太多。定点的修饰倒好(其实所谓定点修饰,并不是完全依赖peg,有一句话,叫case by case,peg-ald是最早被成为定点修饰的,与N末端形成烷基键。其他的都基本是形成个酰胺健,如sc,nhs等等,其实对于这种peg,控制反应ph,使亲核位点质子化或去质子化,都可以使修饰位点的比例发生偏移,有几篇文献就是通过控制反应ph来达到获取同分异构体的目的,进而进行测定先灵的peg-intron就是冻干粉的,说明这个his上的酰胺健是容易水解的,反过来说就是容易被去质子化,低ph下即暴露出亲核位点。而lys的N原子则要高ph才能去质子化。)
求助几篇文献!先谢谢了
Covalent conjugation of Poly(ethylene glycol) to protein and peptides:strategies and methods
methods Mol. Biol 2011 751:95-129
Cojugates of peptide and proteins to polyethylene Glycols
Methods molecular biology 2004, 283,45-70
State of the art in pegylation:The great vesatility achieved after forty years of reseached
Journal of controlled release 2011 vol.7作者: fsdd817 时间: 2013-4-18 16:46