Troxler R F, Offner G D, Xu T, Vanderspek J C, Oppenheim F G
Department of Biochemistry, Boston University School of Medicine, Massachusetts.
J Dent Res. 1990 Jan;69(1):2-6. doi: 10.1177/00220345900690010101.
Histatins are a group of electrophoretically distinct histidine-rich polypeptides with microbicidal activity found in human parotid and submandibular gland secretions. Recently, we have shown that histatins 1, 3, and 5 are homologous proteins that consist of 38, 32, and 24 amino acid residues, respectively, and that these polypeptides kill the pathogenic yeast, Candida albicans. We now describe the isolation and structural characterization of histatins 2, 4, 6, and 7-12, the remaining members of this group of polypeptides. Histatin 2 was found to be identical to the carboxyl terminal 26 residues of histatin 1; histatin 4 was found to be identical to the carboxyl terminal 20 residues of histatin 3; and histatin 6 was found to be identical to histatin 5, but contained an additional carboxyl terminal arginine residue. The amino acid sequences of histatins 7-12 formally correspond to residues 12-24, 13-24, 12-25, 13-25, 5-11, and 5-12, respectively, of histatin 3, but could also arise proteolytically from histatin 5 or 6. These results establish, for the first time, the complete structural relationships between all members of this group of microbicidal proteins in human parotid saliva. The relationship of histatins to one another is discussed in the context of their genetic origin, biosynthesis and secretion into the oral cavity, and potential as reagents in anti-candidal studies.
富组蛋白是一组在电泳中表现不同的富含组氨酸的多肽，具有杀菌活性，存在于人类腮腺和颌下腺分泌物中。最近，我们发现富组蛋白1、3和5是同源蛋白，分别由38、32和24个氨基酸残基组成，并且这些多肽能杀死致病性酵母白色念珠菌。我们现在描述富组蛋白2、4、6以及7 - 12（该组多肽的其余成员）的分离和结构特征。发现富组蛋白2与富组蛋白1的羧基末端26个残基相同；富组蛋白4与富组蛋白3的羧基末端20个残基相同；富组蛋白6与富组蛋白5相同，但含有一个额外的羧基末端精氨酸残基。富组蛋白7 - 12的氨基酸序列分别正式对应于富组蛋白3的第12 - 24、13 - 24、12 - 25、13 - 25、5 - 11和5 - 12位残基，但也可能通过蛋白水解作用从富组蛋白5或6产生。这些结果首次确立了人类腮腺唾液中这组杀菌蛋白所有成员之间完整的结构关系。在它们的遗传起源、生物合成和分泌到口腔中的背景下，以及作为抗念珠菌研究试剂的潜力方面，讨论了富组蛋白彼此之间的关系。
