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Custom · copper-loaded biotin-GHK for streptavidin affinity work
Overview
Biotinyl GHK-Cu is a made-to-order, copper-loaded form of biotin-GHK — the Gly-His-Lys metallopeptide bearing an N-terminal biotin group, with Cu(II) coordinated onto the GHK pocket. It is the affinity-grade companion to the stocked apo ligand: where Biotinoyl Tripeptide-1 is the metal-free biotin-GHK, this active is that same conjugate carrying its copper, characterised for affinity and coordination work. The design intent is squarely coordination-chemistry: keep the Cu(II)/Gly-His-Lys binding intact while the biotin handle provides streptavidin/avidin capture, so the copper metallopeptide can be immobilised onto streptavidin supports or studied under affinity capture. Because biotin occupies the N-terminus that also participates in copper coordination, and because the copper loading on a biotinylated conjugate is route-dependent, this is a custom synthesis: Cupratec does not assign it a fixed catalogue CAS or a single MW — the measured copper content, the biotin conjugation point, and the characterisation figures are specified on the batch COA for the lot you commission. Cupratec supplies it strictly as a cosmetic active; efficacy and any cosmetic claim a finished product makes are the brand's responsibility under its destination-market rules. This is a custom, made-to-order active from the Cu-peptide programme — from 25 g pilot scale through release. Cupratec scopes it with the customer: the copper-loading approach, the intended affinity or formulation context, and the documentation the customer's QC or assay group needs are agreed before synthesis, and the release file is built around what was actually made. Each commissioned lot carries reversed-phase HPLC purity, identity by mass for the conjugate, a measured copper-content figure with the Cu²⁺:peptide relationship reported as-found, and a UV-Vis read to confirm the copper coordination survived the biotin conjugation — the published chemistry shows biotinylated GHK remains able to coordinate Cu(II) and still bind streptavidin, and the COA records that both functions are intact for the lot produced. Lead time is quoted per project. The lot-release and copper-coordination principles are the same ones set out in our Cu²⁺ : peptide ratio field note; for the metal-free starting ligand see Biotinoyl Tripeptide-1.
Who buys this, and why
Cosmetic-peptide buyers fall into two groups: established beauty / med-aesthetic brands extending an existing line, and private-label clients building a catalog from scratch. The first group usually wants lyophilized peptide material plus stability data in their existing carrier matrix; the second usually wants a finished formulation under their label. Both need INCI naming verified, regulator-specific safety files (CPNP for EU, FDA OTC monograph for US where relevant), and packaging-compatibility data.
Primary buyer fit: academic and contract research laboratories and regional distributors and re-sellers.
Specifications
Documentation available on request
Regulatory note
Custom · made to order · from 25 g pilot scale. Biotinyl GHK-Cu is a custom-synthesised cosmetic active; it is not assigned a fixed catalogue CAS or MW — copper content, biotin conjugation point, and characterisation are specified on the batch COA. Supplied as a cosmetic active only, not for compounded human-use preparations. Finished-product cosmetic claims are the brand's to substantiate under its destination-market rules.
Frequently asked questions
Because it is a custom synthesis. The active is biotin-GHK carrying coordinated Cu(II), and both the biotin conjugation and the copper loading are defined by the route agreed for your lot rather than fixed in advance — biotin attaches at the N-terminus that also helps coordinate the copper, so the precise loading is route-dependent. Assigning a single catalogue CAS or MW to a made-to-order metallopeptide conjugate would imply a standardised identity it does not have, so Cupratec reports the real, measured parameters — copper content, identity by mass, biotin conjugation point, purity — on the batch COA for the specific lot produced. The metal-free starting ligand, Biotinoyl Tripeptide-1, does have a fixed identity (CAS 299157-54-3); the copper-loaded custom does not.
It pairs two chemistries in one molecule: the Cu(II)/Gly-His-Lys coordination that defines the GHK metallopeptide, and a biotin handle that binds streptavidin/avidin — one of the strongest non-covalent capture pairs available. That lets the copper metallopeptide be immobilised onto streptavidin supports or studied under affinity capture, which is why it is positioned as an affinity-grade reagent within the copper programme rather than a finished-formulation active. The published chemistry confirms the approach is sound: biotinylated GHK remains able to coordinate Cu(II) and still bind streptavidin, so the conjugate keeps both functions. The release file checks exactly that — a UV-Vis and copper-content read confirms the coordination survived the conjugation for each lot produced.
Cupratec scopes the active with you before synthesis: the copper-loading approach, the affinity or formulation context it has to serve, and the documentation your QC or assay group needs. It runs at 25 g pilot scale first, with the release file — reversed-phase HPLC purity, identity by mass for the conjugate, measured copper content with the Cu²⁺:peptide relationship as-found, and a UV-Vis confirmation that the copper coordination survived biotinylation — built around what was actually produced. Scale-up follows once the pilot lot is qualified against your spec, and lead time is quoted per project rather than held as a stock figure. The underlying lot-release discipline is identical to the stocked complex and is described in our Cu²⁺ : peptide ratio field note.
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