$647.00 - $1943.00
Z-Gly-Gly-Gly-Gly-OH is an N-Cbz-protected tetraglycine fragment with a free C-terminal carboxyl group. It supplies a defined Gly4 segment in one reagent and can reduce the number of individual glycine couplings required in a fragment-based route.
Gly4 is commonly selected when a short, highly flexible peptide spacer is desired. Because glycine has minimal side-chain steric bulk, four consecutive glycine residues can provide substantial conformational freedom without introducing a bulky hydrophobic linker.
Product Information
| Product Name | Z-Gly-Gly-Gly-Gly-OH |
| Catalog No. | AS4091 |
| CAS No. | 7770-50-5 |
| Molecular Formula | C16H20N4O7 |
| Molecular Weight | 380.36 g/mol |
| Chemical Identity | Cbz-Gly-Gly-Gly-Gly-OH |
| Building Block Type | Cbz-protected tetrapeptide fragment |
| Primary Applications | Flexible peptide spacers, protected-fragment synthesis, convergent assembly and linker-containing peptide design |
Gly4 as a Flexible Peptide Spacer
A Gly4 segment can increase distance and conformational freedom between neighboring functional regions. This can be useful in peptide conjugates, affinity constructs and modular peptide designs, but a longer flexible spacer is not always better. Flexibility can also alter proteolysis, effective local concentration and the orientation of attached groups. The shorter Z-Gly-Gly-Gly-OH Gly3 fragment provides a direct chain-length comparison when one fewer glycine is preferred.
Why Buy Gly4 as a Preassembled Fragment?
Stepwise glycine coupling is usually straightforward, but every cycle still introduces opportunities for incomplete reaction and chain-length impurities. A characterized Gly4 fragment moves three peptide bonds into the starting material. We consider this most useful when the Gly4 motif is repeated across several targets or when a solution-phase or convergent route benefits from fewer individual transformations.
Chain-Length QC Matters for Oligoglycine Products
Gly3, Gly4 and Gly5 differ by one glycine unit, so exact chain-length identification should be part of incoming QC. LC-MS is particularly useful for confirming the oligoglycine length, while HPLC helps assess deletion or extension-related impurities. The accumulation of small stepwise inefficiencies in longer peptide assembly is also illustrated in our practical SPPS guide.
Cbz Protection and Downstream Extension
The N-terminal Cbz group protects the Gly4 amine while the C-terminal carboxyl remains available for activation. If later deprotection will use hydrogenolysis, the complete molecule should be checked for reducible groups before the route is fixed.
Procurement and QC Considerations
Confirm CAS 7770-50-5, C16H20N4O7, MW 380.36 g/mol, Gly4 chain length and N-terminal Cbz protection. We recommend matching the full sequence notation and mass rather than relying on a generic “oligoglycine” description.
Product Documents
A Safety Data Sheet (SDS / MSDS) is available for this product to support laboratory handling, storage and safety assessment.
MSDS_Z-Gly-Gly-Gly-Gly-OH_AS4091
Certificates of Analysis (COAs) are batch-specific. Please contact us to request the COA for your product, and we will provide it by email.
Frequently Asked Questions
What is Z-Gly-Gly-Gly-Gly-OH used for?
It is used as a protected Gly4 fragment in flexible linker motifs, convergent peptide synthesis and short-fragment assembly.
How is it different from Z-Gly-Gly-Gly-OH?
It contains one additional glycine residue, increasing chain length and potentially increasing spacer flexibility.
Does the product have a free C-terminal carboxyl?
Yes. The terminal glycine carboxyl group can be activated for further coupling.
Related Technical Resources
For a complete Gly-rich or linker-containing sequence, Alan Scientific can evaluate synthesis, purification and modification requirements through our custom peptide synthesis service.