Histatins, a novel family of histidine-rich proteins in human parotid secretion. Isolation, characterization, primary structure, and fungistatic effects on Candida albicans.

F G Oppenheim,T Xu,F M Mcmillian,S M Levitz,R D Diamond,G D Offner,R F Troxler

doi:10.1016/s0021-9258(18)68522-9

Abstract

Histatins 1, 3, and 5 from human parotid secretion were isolated by gel filtration on Bio-Gel P-2 and reverse phase high performance liquid chromatography. The complete amino acid sequences of histatins determined by automated Edman degradation of the proteins, Staphylococcus aureus V8 protease, and tryptic peptides, are as follows: (Sequence: see text). Histatins 1, 3, and 5 contain 38, 32, and 24 amino acid residues, have molecular weights of 4929, 4063, and 3037, respectively, and contain 7 residues of histidine. Histatin 1 contains 1 mol of phosphate/mol of protein; histatins 3 and 5 lack phosphate. With the exception of Glu (residue 4) and Arg (residue 11) in histatin 1, the first 22 amino acid residues of all three histatins are identical, and the carboxyl-terminal 7 residues of histatins 1 and 3 are also identical. The sequence, -Glu-Phe-Pro-Phe-Tyr-Gly-Asp-Tyr-Gly- (residues 23-29), in histatin 1 is absent in histatin 3; and the sequence, -Gly-Tyr-Arg- (residues 23-25), in histatin 3 is absent in histatin 1. The complete sequence of histatin 5 is contained within the amino terminal 24 residues of histatin 3. The structural data suggest that histatins 1 and 3 are derived from different structural genes, whereas histatin 5 is a proteolytic product of histatin 3. All three histatins exhibit the ability to kill the pathogenic yeast, Candida albicans.

Highlights

Histatins [1, 3], and 5 from human parotid secretion were isolated by gel filtration onBio-Gel P-2 and reverse phase high performance liquid chromatography
Based on the primary structures and antimicrobial properties of these proteins, we propose that the major salivary histidine-rich proteins be named histatins [1,3], and 5
Several other investigators reported amino acid compositions of preparations enriched with respect to basic histidine-rich proteins (16, 18, 19)

Summary

Human parotid and submandibular glands secrete at least

40 electrophoretically identifiable proteins and peptides, relatively fewof these major salivary constituents. Unlike PRPs andstatherin, we have shown acid residues, have molecular weights of 4929, 4063, that neutral HRP plays an additional biologicrole in the and 3037, respectively, and contain 7 residues of his- host’s nonimmune defense system. Purified mixture of these proteins have been (residues 23-29), in histatin 1 is absent in histatin 3; shown to exhibit antibacterial and antifungal activities (14and the sequence, -Gly-Tyr-Arg- (residues 23-25), in 16) The fact that these proteins display a genetic polymorhistatin 3 is absent in histati1n. Based on the primary structures and antimicrobial properties of these proteins, we propose that the major salivary histidine-rich proteins be named histatins [1,3], and 5

DISCUSSION

Histatins in HumaPnarotid Secretion

Human inHistatins