I am using Cocktail with 10% Tips, 5% phenol, 5% H2O, 80% TFA , for cleaving peptide from resin. The peptides have cysteine.
Triisopropylsilane quenches trityl cations.
We have ACQUITY UPLC Peptide BEH C18, 130Ao,1.7um, 2.1*150mm for Peptide mapping. The mobile phase which were tried 1) A: 0.045% H2O, B:.045%ACN 2)A: 0.045% H2O, B:.045%ACN Various gradient were...
05 June 2019 2,330 2 View
Single cyclic peptide in LC having two peaks.
04 May 2019 9,383 7 View
I am trying to detect free thiol in protein. But the confirmation of free thiol with DTNB should be done visibly (by colour change).I have already tested this with benzyl mercaptan and cystiene...
03 April 2019 1,411 4 View
I have synthesized compound which contains amide bond, in column chromatography this compound sticking to silica? Is the use of alumina in place of silica resolve this problem?
31 December 2016 6,398 7 View
If the peptides reaction were done at 30% DMSO and Phosphate buffer (0.1M, pH 7.0) with small organic molecule, so how to prepare the sample for this reaction mixture , If mobile phase for LCMS...
10 November 2016 8,531 1 View
I am trying reactions of peptide with organic molecule in phosphate buffer (pH 7.0) .But while monitoring the reaction by LCMS due to higher salt concentration ,I am not getting the Mass...
08 September 2016 3,003 3 View
I have synthesized few peptides containing cysteine, but in this case the peptide have sulfur in oxidized form (sulfoxide not disulfide).I am using solid phase peptide synthesizer.
07 August 2016 8,849 11 View
I want to modify cysteine of this protein with different electrophiles,so the cystiene should be solvent exposed.And its molecular weight should be less than 30 Kda.
07 August 2016 4,479 3 View
Can I get the proteins which has single cysteine with molecular weight less than 30kilodalton?
04 May 2016 5,225 2 View
We intend to study the interaction between peptides and polymer (like PP, PE and PS) through MD simulations using Martini force fields ( Martini 2 for PP and Martini 3 for PE, PS). We have...
08 August 2024 4,842 0 View
Hi, we have measured tryptic peptides using both DDA and DIA method on QExactive. In DDA replicates i saw unusual intensity drops occurring at the same sections of chromatograms in DDA replicates...
07 August 2024 3,218 4 View
Hello, I am currently analyzing some phosphoproteomics data, but I have peptides with multiple phosphorylation sites or phosphorylations together with carbamidomethylation or oxidation. How can I...
04 August 2024 8,432 3 View
Recently I'm trying to use Sep-pack C18 1 cc Vac Cartridge (Waters: SKU: WAT054955) to desalt digested peptides. However, the recovery rate is usually 40-60%. What is the normal recovery rate?
31 July 2024 6,544 11 View
Hello everyone, I am currently working on a protein that is 10x his-tagged and positively charged (predicted pI=10.16). But when I tried to use Ni-NTA column to purify the protein, it's not...
24 July 2024 7,293 4 View
The resin bonded carbon containing refractories are aged before use. How time of aging is determined? And mechanism behind aging.
23 July 2024 3,205 0 View
Hello, I am experiencing an issue with mixing micro powder with resin in a 3D printer. The problem is that sedimentation occurs after a short period (about half an hour to an hour). Could you...
23 July 2024 1,672 0 View
Methionine, cysteine, homocysteine, and taurine are the 4 common sulfur-containing amino acids, but only the first 2 are incorporated into proteins. Sulfur belongs to the same group in the...
22 July 2024 4,273 4 View
https://en.wikipedia.org/wiki/Viscosity
21 July 2024 3,089 4 View
So i have a few peptides (synthesized by SPPS and not cleaved from resin) and I want to add a maleimide label. We have NHS-PEG-Maleimide and from literature it is evident that the free amine group...
18 July 2024 4,075 3 View