The first four residues of thymosin beta-4 are released as a peptide with a literature of its own

Published 26 October 2026 · REVIVE LAB UAE Research Desk · 5 min read
Prolyl oligopeptidase cleaves thymosin beta-4 after proline 4, releasing the acetylated tetrapeptide Ac-Ser-Asp-Lys-Pro, known as Ac-SDKP. It was first identified as an inhibitor of haematopoietic stem cell proliferation and is now studied as an antifibrotic and anti-inflammatory peptide. It is degraded almost exclusively by angiotensin-converting enzyme, so inhibitors of that enzyme raise its level several-fold, which has been proposed as part of how those medicines reduce fibrosis. Some effects attributed to thymosin beta-4 in animal models have been traced to this fragment.

The cleavage

Prolyl oligopeptidase cuts on the carboxyl side of proline in short peptides and unstructured regions. Thymosin beta-4 has a proline at position 4, and the enzyme releases the first four residues. Because thymosin beta-4 is abundant in most cells, Ac-SDKP is continuously produced and is found in plasma and tissues at nanomolar concentration.

The tetrapeptide retains the acetyl group of the parent.

Its own literature

Ac-SDKP reduces collagen deposition and inflammatory cell infiltration in rodent models of cardiac, renal and pulmonary fibrosis, and its plasma level rises in people taking angiotensin-converting enzyme inhibitors. Several groups have proposed that part of the cardiac benefit seen with thymosin beta-4 in mice is mediated by its conversion to Ac-SDKP, which complicates attribution in that literature.

A 17-residue fragment of thymosin beta-4 covering the actin-binding region would not contain the Ac-SDKP sequence unless it included the amino terminus.

Why it is here

Because the metabolite is part of the established biology of the parent protein and because it illustrates that a 43-residue peptide can act through a fragment of itself. Which fragment the pack contains is a matter for the certificate.

The BPC-157 + TB500 blend is supplied by REVIVE LAB UAE for laboratory research use only, with identity by mass spectrometry and purity by HPLC for each component of the batch. It is not for human or veterinary use, and no dosing, administration or protocol guidance is provided.

What it costs

FormatStrengthPriceAvailability
BPC-157 + TB500 Pack5 mg + 5 mgAED 510In stock

Delivery is AED 40 flat and free on orders over AED 700. Payment is cash on delivery anywhere in the UAE, or USDT (TRC20) in advance, which takes 5% off the order total.

Frequently asked

The cleavage?

Prolyl oligopeptidase cuts on the carboxyl side of proline in short peptides and unstructured regions. Thymosin beta-4 has a proline at position 4, and the enzyme releases the first four residues. Because thymosin beta-4 is abundant in most cells, Ac-SDKP is continuously produced and is found in plasma and tissues at nanomolar concentration.

Does REVIVE LAB UAE provide dosing guidance?

No. REVIVE LAB UAE supplies research materials and provides no dosing, administration or protocol guidance of any kind. Every product is sold for laboratory research use only and is not for human or veterinary consumption.

How fast is delivery in the UAE?

Stock is held in Dubai. An order confirmed before 4 PM Dubai time is dispatched the same working day, reaching Dubai and Abu Dhabi the same day and the remaining emirates within 24 hours. Delivery is AED 40 flat and free over AED 700.

BPC-157 + TB500 Pack — in stock, dispatched from Dubai
HPLC-verified, lot certificate on every carton, 24-hour delivery nationwide. Browse the catalogue → All peptides UAE

Related reading

Supplied for laboratory research use only. Not for human or veterinary consumption. REVIVE LAB UAE provides no dosing, administration or protocol guidance.