Thymosin Alpha-1 vs Beta-4: two sequences

01 / Comparison

Thymosin alpha-1 vs beta-4, side by side.

The two share a family name, not a sequence. Thymosin alpha-1 is a 28-residue chain; thymosin beta-4 is a separate 43-residue chain with a different sequence. Both begin with an acetylated serine.

Thymosin alpha-1 and beta-4
	Thymosin alpha-1	Thymosin beta-4
Length	28 residues	43 residues
N-terminal residue	Serine, acetylated	Serine, acetylated
Sequence	SDAAVDTSSEITTKDLKEKKEVVEEAEN	A different 43-residue chain
Public record	UniProt P06454, peptide 2–29	UniProt P62328, chain 2–44

Reference values from public records, not a Pioneer lot specification.

TB-500TB-500, supplied here as the 43-amino-acid form, the same length as thymosin beta-4.

References: [3][4][5]

02 / Molecular architecture

A closer look at the chain.

Early sequence analysis described an acidic peptide with an acetylated N-terminal serine. Its identity depends on both residue order and that terminal modification.

Pioneer / Reference notesMolecular features

28 amino acids
N-terminal acetylserine
Alpha-thymosin identity

Ser
Asp
Ala
Ala
Val
Asp
Thr
Ser
Ser
Glu
Ile
Thr
Thr
Lys
Asp
Leu
Lys
Glu
Lys
Lys
Glu
Val
Val
Glu
Glu
Ala
Glu
Asn

SDAAVDTSSEITTKDLKEKKEVVEEAEN reference sequence, read from the N-terminus; the serine at position 1 is acetylated. Salt form must be checked separately.

Reference information: [1][2][3][4][5]. Actual lot identity must be verified separately.

The acetyl group belongs in the reference.

The sequence analysis identifies a twenty-eight-residue peptide beginning with an acetylated serine. Acetylation describes the terminal chemistry rather than an extra amino acid. Omitting it while retaining the residue list leaves out part of the reference identity.

Alpha and beta names are not size variants.

The thymosin family includes distinct peptide identities. Alpha-1 and beta-4 do not name two vial sizes of one molecule or interchangeable versions of a single sequence. Sequence-focused references are therefore more useful than grouping materials solely under the broad thymosin name.

Structure and research references: [1][2][3][4][5]

03 / Read the evidence

Research & analytical context.

The sequence papers characterize a 28-residue peptide with an acetylated N-terminal serine. Residue order and the acetyl group distinguish this reference from other polypeptides carrying the thymosin name.

Read the references: [1][2][3][4][5].

The distinction that matters

Alpha-1 and beta-4 are different thymosins with distinct sequences. Match the complete identity rather than grouping their analytical records under the family name alone.

04 / From reference to record

Know the lot, too.

A publication describes its own test material. Your lot’s certificate describes what was tested on that lot. Keep the compound name, batch number and reported methods together when reviewing a result.

Identity & composition

Check sequence or chemical form, terminal modifications, counterion and—where relevant—each blend component.

Analytical results

Read purity, content, sterility and endotoxin results as separate measurements. Only call a test passed when the actual report supports it.

Handling & storage notes

Lyophilized material: Store at −20°C; protect from light and moisture.

Follow the material-specific label and supporting storage documentation. These temperatures do not establish a shelf life.

How to store lyophilized peptides

View Thymosin Alpha-1 sizes View the COA library

05 / Reference questions

A few details, explained.

Is thymosin alpha-1 a form of thymosin beta-4?

No. Alpha-1 is a 28-residue chain and beta-4 a 43-residue chain with a different sequence; both begin with an acetylated serine. The shared family name does not make one a fragment or a variant of the other.

Is N-terminal acetylation included in the residue count?

The acetyl group is a modification on the reference peptide, not an additional amino-acid residue. Both the count and the terminal chemistry should be retained in a complete description.

Read alongside the references: [1][2][3][4][5]

06 / Continue reading

Go to the source.

Each source is labeled by its type. External sources are not Pioneer batch certificates.