GSI has prepared modified peptides that can be fluorescently labeled, biotinylated, phophorylated, acetylated, or have one or more disulfides (see available peptide modifications). GSI has prepared >100,000 peptides for scientists all over the world. GSI products and services have been referenced in several hundreds peer reviewed publications. GSI peptide chemists can help you make peptides tailored to your specific requirements from mg to grams and purities approaching 98-100%.
If you need a custom peptide, please contact us with your needs and take advantage of our expertise. We will be happy to provide a cost estimates and turn around time. Use on-line price quote request form.
Custom Protein Sequence Analyses-General Price Guidelines
Free Services: Selection of Antigenic Peptides, BLAST searches-This service is FREE to all customers who order peptides or antibodies from GSI. There will be a nominal charge for the services without any orders.
Genemed Synthesis Inc (GSI) uses proprietary programs and to find antigenic peptides from gene/protein sequences supplied by researchers. We can take into account any preference to target antibodies to a given region, avoid conserved regions and produce antibodies that are isoform specific.
GSI will perform thorough analyses of protein sequences to identify Signal peptide, Transmembrane domains, and other common structural motifs. This strategy help avoid regions that may be conserved in related isoform or a protein family. GSI typically performs the following analyses on a protein sequence.
1. Identification of specific antigenic peptides. Analyze and find antigenic peptides based upon antigenicity, hydrophilicity, and accessibility parameters. We try to find peptide regions (10-25 aa) that are antigenic, hydrophilic, and accessible.
2. BLAST searches. All recommended antigenic peptides are then subjected to BLAST to confirm specificity of antigenic peptides.
3. Proteins Secondary Structure Analyses for the presence of following motifs.
- Signal peptide (GvH: von Heijne’s method for signal seq. Recognition)
- Transmembrane domains (ALOM: Klein et al’s method for TM region allocation)
- Mitochondrial targeting seq. (MITDISC)
- Nuclear localization signals (NUDISC)
- ER retention motif (KDEL)
- Transport motif from cell surface to Golgi (memYORL)
- PROSITE DNA binding motifs Leucine zipper pattern
- Reinhardt’s method for Cytoplasmic/Nuclear discrimination
5. Multiple Sequence alignment using ClustalW
How to submit sequence to us for analyses:
Please send your name, complete address, and phone, and fax, email addresses preferably by email or fax. We will send our analyses by email or fax within 1-3 days. All information provided to us remains confidential. If you wish to submit a sequence for the identification of antigenic peptides for making antibodies, please provide the following information by email.
1. Name(S) of the protein, gene accession # (if available), and amino acid sequence (single letter code) by email.
2. Sequence alignment of all related proteins, if available, by fax. This will help us in avoiding regions that are conserved.
3. Preferred domains or regions (N or C-terminal) or regions to avoid.
4. Any peptide(s) that have already been selected.