IC₅₀: 0.57 μM (MMP-2), 0.25 μM (MMP-9)

Histatin 5 is a member of a family of low-molecular-weight salivary proteins secreted by parotid, submandibular, and sublingual glands. Using biotinylated gelatin as a substrate, Histatin 5 is found to inhibit the activity of the host matrix metalloproteinases MMP-2 and MMP-9 with IC_50s of 0.57 and 0.25 μM, respectively. To localize the domain responsible for this inhibition, three peptides containing different regions of Histatin 5 are synthesized and tested as inhibitors of MMP-9. Peptides comprising residues 1 to 14 and residues 4 to 15 of Histatin 5 show much lower inhibitory activities (IC_50s, 21.4 and 20.5 μM, respectively), while a peptide comprising residues 9 to 22 showed identical activity to Histatin 5 against MMP-9. Kinetic analysis of the inhibition of the Arg-gingipain reveals that Histatin 5 is a competitive inhibitor, affecting only the Km with a Ki of 15 μM ^[1] . Histatin 5 is an inhibitor of mitochondrial respiration.The human salivary antifungal peptide Histatin 5 is taken up by Candida albicans cells and associates intracellularly with mitochondria. Histatin 5 inhibits respiration of isolated C. albicans mitochondria as well as the respiration of intact blastoconidia in a dose and time-dependent manner. Histatin 5 at a concentration of 33 uM inhibits state 2 respiration^[2] .

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

3150.31

C???H???N??F?O??

Asp-Ser-His-Ala-Lys-Arg-His-His-Gly-Tyr-Lys-Arg-Lys-Phe-His-Glu-Lys-His-His-Ser-His-Arg-Gly-Tyr

DSHAKRHHGYKRKFHEKHHSHRGY

富组蛋白5三氟乙酸盐

Room temperature in continental US; may vary elsewhere.

Powder-80°C2 years-20°C1 yearIn solvent-80°C6 months-20°C1 month

In Vitro: 

H₂O

Peptide Solubility and Storage Guidelines:

1.  Calculate the length of the peptide.

2.  Calculate the overall charge of the entire peptide according to the following table:

 ContentsAssign valueAcidic amino acidAsp (D), Glu (E), and the C-terminal -COOH.-1Basic amino acidArg (R), Lys (K), His (H), and the N-terminal -NH2+1Neutral amino acidGly (G), Ala (A), Leu (L), Ile (I), Val (V), Cys (C), Met (M), Thr (T), Ser (S), Phe (F), Tyr (Y), Trp (W), Pro (P), Asn (N), Gln (Q)0

3.  Recommended solution:

Overall charge of peptideDetailsNegative (<0)1.  Try to dissolve the peptide in water first.2.  If water fails, add NH4OH (<50 μL).3.  If the peptide still does not dissolve, add DMSO (50-100 μL) to solubilize the peptide.Positive (>0)1.  Try to dissolve the peptide in water first.2.  If water fails, try dissolving the peptide in a 10%-30% acetic acid solution.3.  If the peptide still does not dissolve, try dissolving the peptide in a small amount of DMSO.Zero (=0)1.  Try to dissolve the peptide in organic solvent (acetonitrile, methanol, etc.) first.2.  For very hydrophobic peptides, try dissolving the peptide in a small amount of DMSO, and then dilute the solution with water to the desired concentration.

• [1]. Gusman H, et al. Salivary histatin 5 is an inhibitor of both host and bacterial enzymes implicated in periodontaldisease. Infect Immun. 2001 Mar;69(3):1402-8.

  [2]. Helmerhorst EJ, et al. The human salivary peptide histatin 5 exerts its antifungal activity through the formation ofreactive oxygen species. Proc Natl Acad Sci U S A. 2001 Dec 4;98(25):14637-42.