[Isolation, purification and antibacterial activities of salivary histidine-rich polypeptides].
OBJECTIVE
To isolate and purify salivary histidine-rich-polypeptides (HRPs) and observe their antibacterial activities.


METHODS
By using of preparative acid urea polyacrylamide gel electrophoresis (AU-PAGE), three major HRPs(HRP-1, HRP-3 and HRP-5) were purified from parotid saliva collected from healthy adults. Their antibacterial activities were tested in the ultrasensitive antibacterial assay, named radial diffusion assay.


RESULTS
Each fraction of the three purified HRPs appeared as a single protein zone both in AU-PAGE and Tricine-SDS-PAGE. Their molecular weights are 3-5 kD as determined by Tricine-SDS-PAGE. All the three major HRPs showed potent bactericidal effects on Streptococcus mutans MT6R and Staphylococcus aureas ATCC25923. As to Escherichia coli ML-35P and Pseudomonas aeruginosa ATCC27853, HRP-3 and HRP-5 also demonstrated significant antibacterial activities, whereas HRP-1 did not show any inhibitory effects on the viability of them.


CONCLUSIONS
The above results suggested that the method of preparative AU-PAGE we used in this study has the benefits of high resolution, simple manipulation and perfect results of purification. HRPs are important components to prevent oral tissue from bacterial infections, therefore play a potent role in the maintenance of the oral health.
Luo
H
H
College of Stomatology, West China University of Medical Sciences.
Huang
N
N
Yang
M
M
Tang
B
B
Wu
Q
Q
Wang
B
B
D000328:Adult; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000187:drug effects; D006639:Histidine; D006801:Humans; D010455:Peptides; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D012471:Salivary Proteins and Peptides / Q000302:isolation & purification* / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects; D013295:Streptococcus mutans / Q000187:drug effects*
D010455:Peptides; D012471:Salivary Proteins and Peptides; D006639:Histidine