Science Forums Biology Forum Molecular Biology Forum Physics Chemistry Forum At ph=4, what is the charge of the peptide GET?

 Peptide Forum Peptide Forum. Ask and discuss questions on peptide protocols, custom peptide synthesis, peptide identification and peptide sequencing.

# At ph=4, what is the charge of the peptide GET?

## At ph=4, what is the charge of the peptide GET? - Peptide Forum

### At ph=4, what is the charge of the peptide GET? - Peptide Forum. Ask and discuss questions on peptide protocols, custom peptide synthesis, peptide identification and peptide sequencing.

#1
01-31-2013, 02:16 AM
Pipette Filler

Join Date: Aug 2007
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
At ph=4, what is the charge of the peptide GET?

At ph=4, what is the charge of the peptide GET
#2
01-31-2013, 03:15 AM
Pipette Filler

Join Date: Jul 2009
Posts: 9
Thanks: 0
Thanked 0 Times in 0 Posts

The N-terminal amino group will have a charge of +1 because its pKa is around 9 or so. Likewise, the C-terminal carboxyl group will have a charge of -1 because its pKa is around 2.1 or so. Now, the only side chain that can be ionized is the carboxyl group of glutamic acid (E). Its pKa is about 4.25. Since this is slightly above 4, more of the glu carboxyl groups will be un-ionized, and the molecule will still have a slight negative charge. If the pH was exactly equal to the pKa of the glu carboxyl, you could say that the molecule would have a net charge of -1/2. Since you are at a pH a little below the pKa, the net charge will be less than -1/2, but it won't be 0.

You could actually use the Henderson-Hasselbalch equation to calculate the fraction of side chains that are ionized and calculate a specific charge, but that's probably not what they want you to do.

 Tags charge , peptide , ph4

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home General Science Forums     Biology Forum     New Member Introductions Forum     Chemistry Forum         Organic Chemistry Forum     Physics Forum     General Science Questions and Layperson Board         Science and Religion Forum         Zoology Forum     Environmental Sciences and Issues General Forum     Chit Chat         Science and Lab Jokes     Article Discussion     Molecular Biology News and Announcements         Conferences , Symposiums and Meetings         Molecular Station Suggestion Forum         Instructions for Posting, Help, and Frequently Asked Questions     Science News and Views         Molecular Biology Lectures and Videos     Science Careers         Post-doctoral         Medical School         Ph.D Doctor of Philosophy         Science Jobs Forum Molecular Research Topics Forum     PCR - Polymerase Chain Reaction Forum         Real-Time PCR and Quantitative PCR Forum     Bioinformatics         BioStatistics Forum     Molecular Biology Techniques         Molecular Cloning Forum         Electrophoretic Mobility Shift Assay Forum         Agarose Gel Electrophoresis Forum         BioPhysics Forum         Gene Therapy     Cell Biology and Cell Culture         Apoptosis, Autophagy, and Necrosis Forum         Flow Cytometry Forum         Transfection Forum         Confocal - Microscopy Imaging Techniques         Immunology and Host-Pathogen Interactions         Signalling Biology         Stem Cell Forum     Basic Lab Protocols and Techniques         SDS-PAGE Gel Electrophoresis Forum     DNA Techniques         DNA Extraction Forum         cDNA Forum     Epigenetics Forum: DNA Methylation, Histone and Chromatin Study         ChIP Chromatin Immunoprecipitation Forum     Protein Science         Antibody Forum             Immunoprecipitation Forum         Western Blot Forum         Protein Crystallography Forum         Recombinant Protein Forum         ELISA Assay Forum         Protein Forum     Proteomics Forum         Peptide Forum         Mass Spectrometry Forum         2-D Gel Electrophoresis Forum     Omics and Genomics Forum         Microarrays Forum         Genomics Forum     RNA Techniques Forum         RNAi and SiRNA Forum     Histology Forum         Immunohistochemistry Forum         Immunocytochemistry Forum         Electron Microscopy Forum         Immunofluorescence Forum     Protocols and Methods Forum     Molecular Biology Articles and Protocols     Animal and Molecular Model Systems         Drosophila Forum         Yeast Forum         Zebrafish Forum         Botany Forum         C Elegans Forum         Arabidopsis and Plant Biology         Microbiology Forum         Knockout Mouse Forum     Chromatography Forum Products and Vendor Discussion     Molecular Biology Products and Vendors         Bad Product/Service? Post Here         Lab Equipment Discussion and Reviews Regional Molecular Biology Discussion     Forum Chemie     Forum Biologie     Forum Biologia     Forum Chimica     Forum Physik     Forum De Chimie     Forum De Physique     Forum Chemia     中国人分子的生物学论坛 Chinese     Greek Molecular Biology Forums     分子生物学のフォーラム Japanese     ميدان فارسى. Persian Molecular Biology     [أربيك] علم ساحة- Arabic     Forum de Biologie Moleculaire     Forum Biologia Molecolare     Forum die Molekularbiologie     Foro Biologia Molecular

 Similar Threads Thread Thread Starter Forum Replies Last Post molly Peptide Forum 1 10-11-2012 04:06 AM Hermione Granger Peptide Forum 1 10-08-2012 03:44 AM yahman Peptide Forum 2 09-20-2012 06:44 AM dpar Peptide Forum 5 08-20-2010 01:09 PM caltechdude Physics Forum 428 01-21-2005 09:39 PM

All times are GMT. The time now is 12:07 AM.

 Contact Us - Molecular Biology - Archive - Privacy Statement - Top