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Amino acid derivatives
The abbreviations of protecting groups used by Bachem are listed in the glossary. Most of them correspond to literature use. Benzyloxycarbonyl is abbreviated as Z (not Cbz). Allyl ester is used instead of OAll, 2-phenylisopropyl ester instead of OPp.
Substituents can be written out as well, e.g. isopropyl in place of iPr.
If not available for your order, the ADS can be downloaded from the Bachem website.
An ADS (Analytical Datasheet) issued for an amino acid derivative can list:
- Lot number
- Type of product: catalog or custom-synthesized
- Product number
- Product designation
- Molecular formula
- Relative molecular mass
- Tests performed
- Appearance
- Appearance of solution, solvent
- Molecular mass, obtained by mass spectrometry
- Elemental analysis
- Purity (determined by TLC), TLC conditions
- Optical rotation
- Melting Point
- Water content
- Substitution (loaded resins)
If the risk of racemization exists (e.g. during loading of resins), the optical purity is controlled after performing the reaction.
The optical rotation is determined only if reference values can be taken from the literature.
All our resins are based on polystyrene cross-linked with 1% divinylbenzene.
We offer resin derivatives in two particle sizes, 200-400 mesh and 100-200 mesh.
The substitutions of our resins are in the range mentioned in the catalog entry. Please ask our sales department for the loading of the currently available batch.
The resins have to be protected from humidity, especially 2-chlorotrityl chloride resin. PDDM has to be protected from light.
Wang resin (4-alkoxybenzyl alcohol resin), SASRIN (2-methoxy-4-alkoxybenzyl alcohol resin), 2-chlorotrityl chloride resin. As esterification of the C-terminal Fmoc-amino acid can be accompanied by concomitant racemization, we recommend using preloaded resins. They are produced under conditions optimized for minimal racemization and tested for chiral purity.
Resins suitable for the Fmoc-SPPS of peptide amides:
Fmoc-Rink amide AM resin (Fmoc-2,4-dimethoxy-4′-(carboxymethyloxy)-benzhydrylamine linked to Aminomethyl resin), Tricyclic amide linker resin, PAL resin (4-Alkoxy-2,6-dimethoxybenzylamine resin), Xanthenyl linker resin (Sieber amide resin). As removal of Fmoc and loading of the C-terminal amino acid can be easily included in standard Fmoc-SPPS protocols, we do not offer preloaded amide resins.
Derivatives of trifunctional amino acids used in “standard” Fmoc-SPPS:
- Fmoc-Arg(Pbf)-OH, Fmoc-Arg(Pmc)-OH
- Fmoc-Asp(OtBu)-OH
- Fmoc-Asn(Trt)-OH, Fmoc-Asn(Mtt)-OH (for N-terminal Asn)
- Fmoc-Cys(Trt)-OH (single S-S-bridge, or “folding”)
- Fmoc-Gln(Trt)-OH
- Fmoc-Glu(OtBu)-OH
- Fmoc-His(1-Trt)-OH (Fmoc-His(Trt)-OH)
- Fmoc-Lys(Boc)-OH
- Fmoc-Ser(tBu)-OH
- Fmoc-Thr(tBu)-OH
- Fmoc-Trp(Boc)-OH
- Fmoc-Tyr(tBu)-OH
All lateral protecting groups can be removed with TFA.
Merrifield resin (chloromethyl resin) and hydroxymethyl resin, PAM (phenylacetamidomethyl) resin (only available in preloaded form) As esterification of the C-terminal Boc-amino acid can be accompanied by concomitant racemization, we recommend using preloaded resins. They are produced under conditions optimized for minimal racemization and tested for optical purity.
Resins suitable for the Boc-SPPS of peptide amides:
MBHA resin (4-methyl-benzhydrylamine resin), BHA resin (benzhydrylamine resin)
Both resins are offered as hydrochlorides, the amino group has to be liberated before coupling the C-terminal Boc-amino acid. As the loading step can be easily included in standard Boc-SPPS protocols, we do not offer preloaded amide resins.
Derivatives of trifunctional amino acids for “standard” Boc-SPPS:
- Boc-Arg(Tos)-OH
- Boc-Asp(OcHex)-OH
- Boc-Asn(Xan)-OH
- Boc-Cys(Mob)-OH, Boc-Cys(MBzl)-OH
- Boc-Gln(Xan)-OH
- Boc-Glu(OcHex)-OH
- Boc-His(Tos)-OH
- Boc-Lys(2-chloro-Z)-OH
- Boc-Ser(Bzl)-OH
- Boc-Thr(Bzl)-OH
- Boc-Trp-OH, Boc-Trp(For)-OH
- Boc-Tyr(2-bromo-Bzl)-OH, Boc-Tyr(2,6-dichloro-Bzl)-OH
All lateral protecting groups can be removed with HF (removal of For only in the presence of a thiol).
Wang resin (4-alkoxybenzyl alcohol resin), SASRIN (2-methoxy-4-alkoxybenzyl alcohol resin), 2-chlorotrityl chloride resin.
Resins suitable for Boc-SPPS:
Merrifield resin (chloromethyl resin) and hydroxymethyl resin, PAM (phenylacetamidomethyl) resin (only available in preloaded form)
As esterification of the C-terminal amino acid can be accompanied by concomitant racemization, we recommend using preloaded resins. They are produced under conditions optimized for minimal racemization and tested for optical purity.
Racemization can be suppressed when reacting the carboxylate of the protected amino acid with a resin halogenide (2-chlorotrityl chloride resin, Merrifield resin).
The resins have to be protected from humidity.
Fmoc-Pro-DHPP-® (D-1830) represents a more acid-stable alternative to 2-chlorotrityl resin.
Or, Fmoc amino acids can be coupled smoothly and practically devoid of racemization to diphenyldiazomethane resin (PDDM resin). Fmoc Asp- and Glu-derivatives can be easily attached to this resin by their side chains.
Fmoc-Rink amide AM resin (Fmoc-2,4-dimethoxy-4′-(carboxymethyloxy)-benzhydrylamine linked to Aminomethyl resin), Tricyclic amide linker resin, PAL resin, Xanthenyl linker resin (Sieber amide resin).
Resins suitable for the Boc-SPPS of peptide amides:
4-Methyl-benzhydrylamine resin (MBHA resin), benzhydrylamine resin (BHA resin)
Both are offered as hydrochlorides, the amino group has to be liberated before coupling the C-terminal Boc-amino acid.
- SASRIN (2-methoxy-4-alkoxybenzyl alcohol resin) and 2-Chlorotrityl resin
- Xanthenyl linker resin (for protected peptide amides)
- SASRIN-carbazate (for protected peptide hydrazides)
Bachem does not offer resins specifically designed for the Boc-SPPS of protected peptides. Such peptides can also be obtained by Boc-SPPS on e.g. Merrifield resin followed by cleavage with nucleophiles.
2-Chlorotrityl resin has been used for the Fmoc-SPPS of peptide alcohols.
Diphenyldiazomethane resin (PDDM resin) can be used as a carrier for the Fmoc-SPPS of peptides, but it is especially suitable for the synthesis of peptide alcohols, which may also be obtained in protected form.
Bachem also offers Ellman’s dihydropyrane resin.
In most cases, lack of crystallinity is the reason for converting amino acid derivatives into DCHA, DEA, or CHA salts. N-protected Amino acid derivatives carrying very acid-labile protecting are offered as salts as to avoid premature cleavage during storage (e.g. Bpoc-Gly-OH • DCHA). For a protocol describing the liberation of the acid please see the Technical Note downloadable from our homepage.
Esters of amino acids have to be converted into salts of strong acids as to prevent oligomerization (e.g. H-Ala-OMe • HCl) and increase shelf-stability.
Please see our Technical Note “Conversion of a DCHA salt to the free acid” downloadable from our homepage. Special care has to be taken when liberating amino acids carrying highly acid-sensitive groups as Bpoc.
- Fmoc-4-phosphono-Phe(Bzl)-OH
- Boc-4-phosphono-Phe(Et)2-OH
- O-malonyltyrosine derivative Fmoc-Tyr(malonyl-di-OtBu)-OH.
You will find two families, one containing our 15N-labeled derivatives and the other consisting of our deuterated derivatives, in the amino acids section of our online catalog.
- Fmoc-εAhx-OH, Fmoc-8-aminooctanoic acid (Fmoc-8-Aoc-OH) (both non-polar)
- Fmoc-AEEAc-OH (polar)
For Boc-SPPS:
- Boc-εAhx-OH, 11-(Boc-amino)-undecanoic acid
- N-terminal FITC requires a spacer.
Analysis of peptides
If not available for your order, the ADS can be downloaded from the Bachem website.
You have to enter the product number and the lot number which is imprinted on the label of the vial and mentioned on the invoice.
Click on “continue” to get your ADS as pdf file.
An ADS issued for a peptide can list:
- Lot number
- Type of product: catalog or custom-synthesized
- Product number
- Product description: name and sequence
- Molecular formula
- Relative molecular mass
- Tests performed:
- Appearance
- Appearance of solution, solvent
- Molecular mass, obtained by mass spectrometry
- Amino acid analysis
- Purity (determined by HPLC), up to 3 values obtained in different buffer systems
- “Assay” (N-content, as determined by elemental analysis)
An example: NPC 85%,1 mg (gross ) = 0.85 mg (net)
A relatively low peptide content can be expected when a peptide contains a large proportion of basic amino acids, especially arginines.
Molar amount of desired peptide =
Gross weight x NPC (%) x HPLC-purity (%) / Mol. weight x 10’000
An example: Bradykinin acetate salt, gross weight 5 mg
HPLC-purity 98.7%, NPC (“Assay”) 85.0%, Mol. weight 1060.22 g/mol → net 4.195 mg (3.956 µmol)
This value allows calculating concentrations, when dissolving the peptide.
Truncation sequences (which may be generated deliberately by capping steps to avoid the formation of deletion peptides), incompletely deprotected peptides and by-products generated during the synthesis or during the final cleavage may also be found among the impurities.
Molar amount of desired peptide = Gross weight x NPC (%) x HPLC-purity (%) / Mol. weight x 10’000
An example: Bradykinin acetate salt, gross weight 5 mg
HPLC-purity 98.7%, NPC (“Assay”) 85.0%, Mol. weight 1060.22 g/mol → net 4.195 mg (3.956 µmol)
This value allows calculating the amount of solvent required for obtaining a given concentration.
Conditions of sale and ordering
Request a bulk quote here.
- 2 vials – 5% discount
- 3 to 5 vials – 10% discount
- 6 to 9 vials – 15% discount
- 10 to 30 vials – 20% discount
- ≥ 31 vials – 25% discount
Delivery
US & Canada: Orders are shipped standard overnight or second-day via FedEx. UPS and Freight Forwarder services are available upon request at the time of order.
Most catalog and custom products are shipped at ambient temperature. The recommend long-term storage temperature is indicated on the product label.
- Commercial invoice if applicable.
- Packing list.
Analytical Datasheets (Certificates of Analysis) of the products, which can be downloaded from our homepage after having received the order, are included only on request.
All vials contain labels listing the designation and amount of product, storage temperature, safety information, and lot number.
Enzyme substrates
- released 7-amino-4-trifluoromethylcoumarin λexc 395-400 nm, λem 495-505 nm
- released 7-amino-4-methylcoumarin λexc 360-380 nm, λem 440-460 nm
Please see also our Technical Note “Chromophors/Fluorophors: Spectral Properties and Characteristics” which can be downloaded from our homepage.
The quencher absorbs the energy emitted by the fluorophore only as long as they are in close proximity, connected by the peptide chain. Enzymatic hydrolysis causes an increase of fluorescence irrespective of the cleavage position, provided that donor and acceptor are disconnected.
Bachem offers a large choice of FRET substrates for MMPs, ACE, β-secretase and other enzymes. For an overview of our products you can download our product monograph “FRET Substrates”.
- Abz/various quenchers
- N-Me-Abz/Dnp
- EDANS/DABCYL
- Mca/Dnp
- Trp/Dnp
In most cases, the enzymes are designated according to the BRENDA enzyme data base.
In most cases, the enzymes are designated according to the BRENDA enzyme data base. Or enter the enzyme name into the search field.
Handling of peptides
Peptides should not be subjected to strong light, extreme pH-values, and oxidants.
As peptides are biologically active even in minute amounts, a dust mask, safety goggles, and protective gloves should be worn when handling lyophilizates.
Except for handling very short peptides or large amounts, reconstituting the peptide and aliquoting the resulting solution is preferable to weighing out.
The solubility of a peptide in a solvent or buffer is determined mainly by its polarity, which results from the amino acid composition, and its conformation.
Solubility in water can be expected for peptides containing a large proportion of charged amino acids. As the peptides are usually produced as trifluoroacetate salts, the basic amino acids (Arg, Lys, His) and the N-terminal amino group will be protonated. The aqueous solubility of peptides containing Asp and/or Glu can be improved by adding diluted ammonia, which will generate the ammonium salts.
Polar amino acids as Asn, Gln, Gly, Ser, Thr facilitate reconstitution in water.
DMSO (dimethyl sulfoxide) is a highly suitable solvent for dissolving non-polar peptides (peptides containing a large proportion of Ile, Leu, Met, Phe, Pro, Trp, Val; most fluorophoric and chromophoric peptide substrates), it will also disrupt aggregates. Addition of DMSO (or DMF, acetonitrile, or other highly polar water-miscible solvents) may help to reconstitute a peptide, which is scarcely soluble in water. DMSO should not be used in combination with strong acids as trifluoroacetic acid. Most peptides will dissolve in acetic acid. Cys- and Met-containing peptides require special attention to prevent oxidation of the sulfur.
Reconstitution of peptides, especially long peptides or inner salts, may take time. Gentle warming or short repetitive sonication to accelerate dissolution is usually tolerated.
The intended use may limit the choice of solvents.
We advise against dissolving peptides directly in assay buffer, except if they show a high water-solubility.
Degassed buffers have to be used for reconstituting Cys- and Met-containing peptides. Contrary to sulfoxide formation, the oxidation of the thiol moiety is pH-dependent. Peptides containing free cysteines should be dissolved in acidic buffers.
DMSO should be avoided, especially with peptide trifluoroacetates.
“Fresh” lyophilizates of Aβ (25-35) and (1-40) are still soluble in water (oxygen-free water has to be used), the “aged” peptides may require the addition of acetic acid for dissolution.
Direct dissolution of amyloid peptides in buffers as PBS should not be attempted, better dissolve them first in water or 50% acetic acid and then dilute with the working buffer.
Please see also our Technical Note “Care and Handling of Amyloid Peptides”, which can be downloaded from our website.
Aβ (1-42) solutions in DMSO or aqueous bases can be diluted directly with working buffer. The volatile solvent HFIP is usually evaporated leaving a residue of monomeric, soluble Aβ (1-42), which can be reconstituted with the chosen buffer pH 7.4 as to induce fibrillation.
Lyophilizates contain water, which may be involved in degradation reactions during storage. Peptides containing Asn, Gln, Cys, Met, Trp tend to be less stable. Moreover, the salt form affects stability.
The stability may range from few months to years, if the peptide is kept in a tightly closeed vessel at <-15°C.
The stability of the aliquots may range from weeks to months.
- Oxidation of Met yielding the sulfoxide
- Oxidation of Trp and Tyr
- Oxidation of Cys to cysteic acid
- Deamidation of Asn, Gln, and the C-terminal amide
- Aspartimide formation
- Cleavage of Asn-Pro
- Pyroglutamine formation of N-terminal Gln
- (Cyclization of N-terminal Glu has only rarely been observed)
- Dimerization of Trp and Tyr
- Racemization
Sulfotyrosine-containing peptides may loose their activity due to desulfation, Gla-containg peptides can decarboxylate.
Only solvents, which rapidly dissolve the peptide in the required concentration without damaging the compound, are suitable for analytical purposes. Volatility or high UV-transmission can be additional criteria. This excludes e.g. the use of DMSO.
Nomenclature
In most cases, the term “amino acid” refers to an α-amino acid. Amino and carboxyl moiety are linked to the same carbon atom, the α-carbon. Glycine, α-aminoacetic acid, is the simplest amino acid, the parent compound of this class of substances.
β-alanine is the parent compound of the β-amino acids.
Pyroglutamyl is abbreviated as Pyr (quite a number of abbreviations is in use for this most important peptide modification, IUPAC/IUB: Glp). For designations of other amino acids please see the glossary. Some abbreviations differ from literature use and IUPAC/IUB recommendations.
As the number of amino acids discovered in nature is ever increasing, we prefer to avoid the term “unnatural amino acid” and thus designate all non-proteinogenic amino acids as “unusual amino acids”.
This category also includes the “non-α-amino acids”, as β-amino acids (e.g. isoserine), γ-amino acids (e.g. statine),…,ω-amino acids (e.g. ε-aminocaproic acid, 11-aminoundecaoic acid).
D- and L-enantiomer do not differ in their physical properties, but they rotate the plane of linearly polarized light. Most L-amino acids rotate the light counterclockwise. The rotation angle [α] for a given concentration, solvent, temperature, wavelength, and light path (length of the measuring cell) is specific for an amino acid derivative.
e.g. [α] determined for batches of both enantiomers of Fmoc-phenylalanine measured at 589 nm (NaD line), 24°C, 0.1% in DMF
Fmoc-Phe-OH [α]D24 -39.1°
Fmoc-D-Phe-OH [α]D24 + 39.0°
Enantiomers differ considerably in their biological activity.
H-Ala-OH (and NOT Ala) stands for unmodified L-alanine, H-Ala-NH2 for L-alaninamide, H-Ala-OMe for the methyl ester.
Side chain modifications are put in brackets -Xaa(Y)-:
Fmoc-Lys(Boc)-OH designates an Nα-fmocylated, side-chain (Nε)-bocylated L-lysine.
Three-letter code: N- and C-terminus are specified, H- signifies a free amino terminus, -OH an unmodified C-terminus, -NH2 a peptide amide, e.g. H-Ala-Ala-Ala-OH, H-Ala-D-Ala-Ala-OH, H-Ala-Ala-Ala-NH2.
One-Letter code: Only modified termini are specified, e.g. AAA, Ac-AAA, AAA-NH2.
In case of peptides containing unusual amino acids, the three-letter code abbreviation can be inserted and marked as such by hyphens: Ac-SYS-Nle-EHfRWGKPV-NH2.
Endothelin-1 (human, bovine, dog, mouse, porcine, rat) (ET-1)
Bachem also offers partial sequences of such peptides:
Amyloid β-Protein (25-35)
and N-terminally labeled peptides:
Biotinyl-BNP-32 (human) (Biotinyl-Brain Natriuretic Peptide-32 (human))
Amino acid replacements or modifications are designated by mentioning the newly introduced or modified amino acid(s) and the position of exchange:
(Gly28,Cys30)-Amyloid β-Protein (1-30); (Lys(biotinyl)29)-Cortistatin-29 (human)
Omissions are marked by “Des” (Des-Gly77,Des-His78)-Myelin Basic Protein (68-84) (bovine)
- at the N-terminus e.g. N-acetylation: H-Ala-Gly-… -> Ac-Ala-Gly-… (Ac-AG…)
- at the C-terminus e.g. amidation: …-Gly-Ala-OH -> …-Gly-Ala-NH2 (…GA-NH2)
Both modifications are widespread in nature.
- at the side-chains of amino acids e.g. acetylation of lysine..-Lys-.. -> ..-Lys(Ac)-.. (…K(Ac)…)
NOTE: -Cys- stands for a cysteine residue containing a free thiol group, unless disulfide formation is mentioned explicitly
- at the backbone of the peptide e.g. by incorporation of D-amino acids …-Ala-Leu-D-Phe-Tyr-… (…ALfY…)
Abbreviations have been defined for most modifications, others are written out in full e.g. H-Phe-pyrrolidide, H-Lys(isopropyl)-OH
Our notation does not distinguish between temporary -protecting groups- and permanent modifications of peptides. Not all modifications can be transformed unambiguously into one-letter code, but terminal modifications such as Ac or NH2 or D-amino acids (lowercase letters) or simple side-chain modifications (put in brackets) do not cause difficulties.
One-letter code sequences lack designations of disulfide bridges.
e.g. H-Asn-Arg-Cys-Ser-Gln-Gly-Ser-Cys-Trp-Asn-OH
(Disulfide bond)
NRCSQGSCWN
H-Arg-Asp-Cys-Cys-Thr-Hyp-Hyp-Lys-Lys-Cys-Lys-Asp-Arg-Gln-Cys-Lys-Hyp-Gln-Arg-Cys-Cys-Ala-NH2
(Disulfide bonds between Cys3 and Cys15/Cys4 and Cys20/Cys10 and Cys21)
RDCCT-Hyp-Hyp- KKCKDRQCK-Hyp-QRCCA-NH2
Sequences (three-letter code) of Cys-containing peptides lacking “disulfide bond” (or a similar extension) contain free thiol moieties!
e.g.
H-Tyr-Gly-Gln-Val-Pro-Met-Cys-Asp-Ala-Gly-Glu-Gln-Cys-Ala-Val-OH
free sulfhydryl groups
H-Tyr-Gly-Gln-Val-Pro-Met-Cys-Asp-Ala-Gly-Glu-Gln-Cys-Ala-Val-OH (disulfide bond)
oxidized sulfhydryls
A protocol for the reversal of inadvertent oxidation of Cys peptides can be downloaded from our website.
Cyclo(-Arg-Gly-Asp-D-Phe-Cys) or c(RGDfC).
Phosphotyrosine H-Tyr(PO3H2)-OH
A phosphopeptide Ac-Tyr(PO3H2)-Tyr(PO3H2)-Tyr(PO3H2)-Ile-Glu-OH
Our derivatives of phosphorylated amino acids are assembled in subfamilies to be found in the families Serine, Threonine, and Tyrosine. The one-letter code equivalents of these phosphorylated amino acids are pS, pT, and pY.
- α-peptide H-Asp-Ala-OH
- β-peptide H-Asp(Ala-OH)-OH = H-β-Asp-Ala-OH
- γ-peptide H-Glu(Ala-OH)-OH = H-γ-Glu-Ala-OH
Bachem offers a large choice of Asp and Glu derivatives suitable for synthesizing isoaspartyl and isoglutamyl peptides e.g. Fmoc-Asp-OtBu, Boc-Glu-OBzl
L-Isoasparagine: H-Asp-NH2
L-Isoglutamine: H-Glu-NH2
Isoasparagine derivatives are assembled in a subfamily filed under Aspartic Acid, isoglutamine derivatives can be found in the Glutamic Acid family.
e.g. N-Me-Ile-OH (not Me-Ile-OH nor H-MeIle-OH), Sar-OH (not H-Sar-OH),
Boc-N-Me-Phe-N-Me-Phe-OH
Cα-methylated amino acids are designated likewise:
e.g. H-α-Me-Phe-OH
We recommend searching the appropriate subfamily of the Histidine family instead of entering the derivative.
Oligonucleotides
Oligonucleotides are tending to become more complex, helping to enable the benefits of oligonucleotide treatments to expand from rare to chronic disease, i.e., asthma, diabetes, chronic liver diseases – and into many more therapeutic indications. This pace keeps increasing with more than 150 clinical trials for oligonucleotide products currently ongoing!
Oligonucleotides and peptides are oligomers made of nucleotides and amino acids respectively.
They follow the same basic principle of manufacturing that has been Bachem’s core technology for decades:
- Solid-phase synthesis and protecting groups chemistry
- Chromatography
- Ultra/diafiltration
- Lyophilization
There is also a synergy in the supply chain, for instance the solvents management or the building block sourcing.
For large scale: 0.2 to 2 mol (1-5kg) per batch
For R&D scale: 50-200 mmol (0.1-1kg) per batch
With the new building extension in Bubendorf, we will be also equipped for commercial scale for oligonucleotide production.
We are equipped from small to large scale with:
- Automated oligonucleotide synthesizers
- Automated cleavage and deprotection
- Chromatography for batch and continuous mode
- Automated buffer supply system
- Ultra- and diafiltration
- Clean rooms and lyophilizators
Batch sizes ranging from tens of grams to multi-kilogram quantities.
Peptide synthesis and purification
The source (synthetic/recombinant) is explicitly mentioned in the product entry and included in the designation of recombinant peptides (rec).
Bachem’s peptides are obtained either by “classical” solution-phase synthesis or by solid-phase synthesis (SPPS). The peptide is elongated starting from the C-terminus to the N-terminus of the sequence.
The peptide, linked by its C-terminal amino acid to a carrier resin, an inert, insoluble but swellable polymer, is assembled in the C→ N direction. It is elongated stepwise by coupling suitably protected derivatives of the amino acids constituting its sequence until coupling the N-terminus. After each coupling step, the “temporary” Nα-blocking group has to be removed without affecting the lateral protective groups and the link to the carrier.
The method can be fully automated. Thus, peptides can be obtained by SPPS far more rapidly than in solution, but the method requires large excesses of expensive amino acid derivatives for driving the coupling steps to completion.
e.g. rec Human Growth Hormone (expressed in E.coli)
Except when mentioned otherwise, our peptides are provided as trifluoroacetate salts. Peptides obtained by SPPS come into contact with trifluoroacetic acid (a strong acid) during cleavage from the carrier resin and purification. Generation of other salt forms requires an additional ion-exchange step.
Acidic peptides, i.e. peptides containing a large proportion of Asp and/or Glu, or phospho- or sulfotyrosine, can form salts with bases. Thus, a few acidic peptides are sold as ammonium salts.
Peptides obtained in solution are offered as acetate salts or inner salts, unless mentioned otherwise.
Long peptides usually do not form stoichiometric salts with acids or bases, as low molecular weight bases or acids do.
The purity stated on the ADS for peptides containing free Cys residues signifies the monomer content at the time the analytical HPLC was recorded. As air oxidation cannot be completely prevented in the meantime, we suggest reducing the peptide before use by treatment with dithiothreitol (DTT).
For a short description of the cystine reduction using DTT please see our Technical Note “Reversal of Inadvertent Oxidation of Cys-containing Peptides”, which can be downloaded from the “Service & Support” section of our homepage under “Technical Library”.
They may not be used as drugs. GMP-APIs are products monitored for chemical and biological contaminants applicable to humans.
Amyloid β-Protein (1-42) ↔ Amyloid β-Protein (42-1)
RGDS ↔ RGES
Prion Protein (106-126) (human) ↔ Prion Protein (106-126) (human) (scrambled)
Product catalog
Europe, Asia and rest of world
Tel: +41 58 595 2021
Fax: +41 58 595 2040
Email: sales.ch@bachem.com
North and South Americas
Tel: +1 888 422 2436
+1 888 4BACHEM
+1 310 539 4171
Fax: +1 310 539 9428
Email: sales.us@bachem.com
You can search products on our new product catalog website and submit a quote request to our sales team through the platform.
If you are contacting us outside of normal business hours, please send us a pack or custom/bulk quote request or send us an email using the contact form and we will get back to you within the next business day.
Pre-payment may be required prior to order fulfillment based on the payment agreements set for your company or organization.
Number of vials | Discount |
2 | 5% |
3 to 5 | 10% |
6 to 9 | 15% |
10 or more | Please inquire |
Please contact us for bulk requests and bulk pricing.
We offer express shipping options for our products and the delivery time depends on the selection.
To find the ADS of a specific lot, enter the product number and lot number into the ADS lookup to download the appropriate ADS as a pdf file.
Please use the online contact form for your request if you are unable to download the document.
It can also be found by entering the product number into the MSDS lookup to download the appropriate MSDS as a pdf file.
Please use the online contact form for your request if you are unable to download the document.
If you are contacting us outside of normal business hours, please send us a pack or custom/bulk quote request or send us an email using the contact form and we will get back to you within the next business day.
- Product name (especially with peptides), e.g. Melittin
- The search function is not case sensitive and you may use Greek letters (α, γ etc.) and upper and lower-case numerals (NH2, Sar1) whenever applicable.
- Bachem’s product number
- CAS number
- Peptide sequence in one- or three-letter code (partial sequences: three-letter code only). For amino acids, please see the FAQ ‘What is the best way to search for an amino acid derivative?’
You may sort the results by price, synonyms, and product name. Results may also be filtered by the application, salt form, the length of the sequence, or the molecular weight.
When entering the three-letter code designation, defining both the N- and C-terminus will lead to the desired product as the top result (if the product is available).
Examples: H-Ser-OH, Ac-Leu-OH, Boc-Val-OH
A list of building blocks or products for peptide synthesis are available under “Amino Acid Derivatives and Reagents”.
When searching for an amino acid sequence by the 1- or 3-letter code, defining both the N- and C-terminus will lead to the desired product in the top results. If not, you will find all of the sequences containing the entered amino acids.
Additional information about substrate or inhibitor binding may be found under the Enzyme tab on the product page if applicable.
The product page includes the product name, product number, sequence, synonyms, a product description, literature references, and more. All of this information is searched for in your entry. Hence the entries containing the search term in their name will not necessarily show up first.
Visit our Knowledge Center for the pdf or read through our Technical Notes. You can access a variety of materials containing information on our products and services, white papers, product flyers (containing product compilations by research topic), technical notes on the handling of our products, and more in our Knowledge Center.
The reference compilation consists of two types of references:
- Bachem product citations: the product used in the study was obtained from Bachem.
- Product citations: references used for preparing the product description.
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