Microbiology Flashcards
what microbes in saliva have antibacterial properties?
cystatins
mucins
what microbes in saliva are anti viral?
cystatins
mucins
what microbes in saliva are for tissue coating?
cystatins
mucins
what microbes in saliva are for lubrication and viscoelasticity?
mucins
what microbes in saliva are for mineralisation?
cystatins
what microbes in saliva are for digestion?
mucins
what microbes in saliva are for buffering?
carbonic anhydrases
histatins
what percentage of the acquired pellicle do glycoproteins constitute?
90%
what makes salivary glycoproteins good for digestion and movement?
lower surface tension
what 2 forms are salivary mucins?
anchored to surface (by D domain)
soluble (arent attached)
what are features of salivary mucins?
adherence to soft tissues etc.
degraded to reveal binding site
degraded to provide nutrition
bind bacteria for mucociliary clearance
degraded to release antibacterial peptides
where would you find mucins with gel forming and membrane bound properties?
ocular gel on eyelids allowing movement
how do mucins become gel forming and membrane bound?
interaction between cystine cross bridges for lipid formation
what is MG1?
oligomeric mucin glycoprotein - gel forming mucin and membrane bound
what is MG2?
monomeric mucin glycoprotein - influence on oral microbiota (attached to surface)
what bacteria does MG1 attract?
S.anguinis
S.mitis
Actinomyces
what phase is MG1 associated with?
soluble phase and rapid flushing out of material
what bacteria does MG2 attract?
S.anguinis
S.gordonii
E.corrodens
S.aureus
P.aeruginosa
what are the antibacterial effects of MG2?
attracts bacterial species
as its cleaved, the peptide kills and inhibits them
what is the role of MG2 under healthy conditions?
control bacteria in the mouth and protect from colonisation
what are PRPs?
proline rich proteins - strong promotors of bacterial adhesion
what gives PRPs structural flexibility?
amino acids
what results in PRPs having different effects?
different breakdown products
what controls calcium and phosphate levels?
amino carboxy terminal in PRPs
what can alter a PRPs structure?
pH
What do PRP interactions depend on?
proline-glutamine carboxy-terminal dipeptide
where would you find acidic PRPs (16kd)?
only saliva
what is the main function of acidic PRPs (16kd)?
bind to hydroxyapatite to control remineralisation
what are the properties of basic PRPs (6-9kd)?
protection
found in other places in the body
soft tissue (fumes in nasal)
charged interactions
where do you find glycosylated PRPs (36kD)?
newly formed pellicle
what does Statherin do?
controls remineralisation on tooth surface by blocking nucleation sites - stops/ controls secondary disposition of calcium phosphate
what structures does statherin have?
C terminus
N terminus
what does statherin inhibit?
candida species
what produces glucans?
oral strep
how may glucans be antiseptic?
if they are on the surface of antibodies they can protect by binding to receptors on the surface of the virus and prevent it entering a cell
how do cystatins function?
interfere with cysteine proteases that are produced by bacteria or are important for entry of viral molecules into the mouth
what are the properties of cysteine?
protect overall degradation of proteins
remineralise calcium and phosphate
what is the role of histatins?
promote wound healing
what do histatins have the ability to do?
bind to zinc
where do you find lysozyme?
tear ducts
what does muramidase do?
breaks down sugar side chains, leaving cross links intact
breaks down the cage around bacteria
what properties does lactoferrin hold?
bacterial and antifungal
what is lactoferrin?
glycoprotein
how does lactoferrin function?
binds to and sequesters iron indirectly (takes molecules away for survival)
