Tear Enzymes

Question 1

Most important enzyme in tears

Answer 1

Lysozyme

Question 2

Is lysozyme found in lysosomes?

Answer 2

No, found in secretions, tears/milk/saliva

Question 3

Imidazole and lysozyme

Answer 3

Competitively inhibits lysozyme

Question 4

Inhibition of lysozyme

Answer 4

• imidazole derivatives
• in gram negative bacteria, the lippolysaccharide acts as a non-competitive inhibitor by highly favored binding with lysozyme

Question 5

Small cysteine rich antimicrobial peptides act mainly by disrupting the structure of bacterial cell membranes and are found in many compartments of the body. Evidence is accumulating that they play a role in defense against pathogens, and they are considered as a part of the innate immune respsone

Answer 5

Defensins

Question 6

Effects viruses and cells

Answer 6

Defensins

Question 7

Most defensins function by

Answer 7

Binding to the microbial cell membrane
Embedding in the bacterial cell membrane
Forming pore-like membrane defects that allow effluent of essential ions and nutrients

Question 8

An artificial human theta-defensin, was shown to be effective against HIV and other viruses, including herpes simplex and influenza A. Act primarily by preventing these viruses from entering their target cells

Answer 8

Retrocylcin

Question 9

Amino acid produced by platelets during coagulation and is directly antibacterial by causing lysis of many gram positive bacteria by acting as a cationic detergent

Answer 9

B-lysine

-Identification of a nonlysozymal bactericidal factor in human tears

Question 10

Multifunctional protein of the transferrin family. It is a globular glycoprotein that is widely represented in various secretory fluids, such as milk, saliva, tears, and nasal secretions

Answer 10

Lactoferrin

Question 11

Helps regulate the absorption of iron in the intestine and delivery of iron to the cells. It also seems to protect against bacterial infection, possibly by preventing the growth of bacteria by depriving them of essential nutrients or by killing bacteria by destroying their cell walls

Answer 11

Lactoferring

Question 12

Lactoferrin in dry eye

Answer 12

Decreases

-Sjogrens

Question 13

Removes components that Ab their a need to grow and can destroy bacterial cell wall

Answer 13

Lactoferrin

Question 14

Function of lactoferrin

Answer 14

Affects the innate immune system, apart from its main biological function, namely binding and transport of iron ions, lactoferrin also has antibacterial, antiviral, anriparasitic, catalytic, anti cancer, and anti allergic functions nad properties

Question 15

Lacoferrin and breast cancer

Answer 15

Can destroy viruses that are associated with breast cancer

-lower levels of lactoferrin correlated with high levels of cancer

Question 16

B lysine: how does it function in terms of destroying a pathogen

Answer 16

Functions as a detergent

Question 17

Small polypeptides that can be easily synthesized in nonproteinacious way and drugs are being tested this way

Answer 17

Defensins

-mimetics

Question 18

What does lysozyme do

Answer 18

• cleaves linkages between sugars and destabilizes the integrity of the cell wall of predominantly gram positive bacfgeria and causes it to rupture
• gram positive
• good in areas exposed with O2
• able to break sugar bonds

Question 19

Lactoferrin facts

Answer 19

Binds irons
Takes up some of the nutrients that the bacteria would need to grow, so it destroys it
Low levels associated with breast cancer
Decreased in Dry eye conditions such as Sjogrens or autoimmune disorders