Other · Histidine-rich salivary peptide fragment
Histatin-2
Also known as Hst2
A salivary Histatin-1 fragment used to examine how proteolytic processing changes histatin structure and molecular interactions.
- Length
- 26 amino acids
- Half-life
- Not well characterised
- Mechanism
- Histatin-2 is a cationic, histidine-rich fragment whose interactions with microbial surfaces and other molecular partners depend on sequence and solution conditions. A specific receptor and a well-resolved, Histatin-2-specific signalling mechanism have not been established.
- Studied in
- Salivary proteolysis studies and comparative microbial or surface-binding assays examine Histatin-2 alongside other histatin-family peptides.
About Histatin-2
Histatin-2 is generally described as a 26-residue, C-terminal processing product of Histatin-1 rather than a separately encoded primary peptide. Histatins were identified through biochemical characterisation of histidine-rich components of human saliva. The commonly assigned Histatin-2 fragment corresponds to Histatin-1 residues 13–38 and therefore lacks the phosphorylated N-terminal serine of its precursor. Exact sequence documentation is essential when comparing historical salivary fractions with contemporary synthetic preparations, since a fraction name alone does not establish molecular identity.
Compared with Histatin-1, Histatin-3 and Histatin-5, Histatin-2 has a smaller dedicated mechanistic literature. Its retained histidines and basic residues support investigation of pH-dependent charge, microbial interactions and peptide processing, but family-level observations should not be presented as established Histatin-2 activities. Appropriate experiments include analytical mapping of salivary degradation products and side-by-side assays using sequence-verified histatins. Neither a unique receptor target nor a generalisable biological half-life is well characterised for this fragment.
Laboratory notes
- Verify the complete sequence and molecular mass rather than relying solely on the Histatin-2 name.
- Distinguish the isolated fragment from Histatin-1 and mixed salivary digests using chromatography and mass spectrometry.
- Standardise pH and salt content when comparing histatin fragments; their charge-dependent behaviour can change substantially between assay buffers.
Storage and reconstitution basics: storage guide.
Questions about Histatin-2
Is Histatin-2 encoded by a separate histatin gene?
It is generally assigned as a proteolytic product of Histatin-1, not as the mature product of a separate Histatin-2 gene.
Does Histatin-2 retain Histatin-1's phosphoserine?
The commonly assigned C-terminal fragment does not include Histatin-1 residue 2 and therefore does not retain that phosphoserine.
Can Histatin-1 migration findings be assigned to Histatin-2?
Not without direct testing. Removing the N-terminal segment changes the molecular structure, and Histatin-2-specific evidence is substantially more limited.
Is Histatin-2 for human use?
No. It is supplied strictly for in-vitro laboratory research and is not for human or animal consumption.
Related research peptides
All products are sold for laboratory research use only. Not for human consumption, not a medicine, not for diagnosing, treating or preventing any condition.