Drug Binding Interactions

Question 1

What do drugs bind to?

Answer 1

Target receptor/enzymes
transport proteins
metabolizing enzymes
additional sites

Question 2

Interaction between drug molecule and receptor depends on ?

Answer 2

functional groups on the receptor and drug
types of bonds that the functional groups can form with one another
number and relative strengths of bonds

Question 3

Covalent bonds

Answer 3

strongest types of bonds
not readily reversible
generally involves a nucleophilic attack and a lone pair of electrons or a negative charge

Question 4

What is required to reverse covalent bonds?

Answer 4

biosynthesis of a new copy or enzymatic cleavage

Question 5

Some compounds that form covalent, irreversible bonds may require?

Answer 5

specific handling and guidelines

Question 6

What are the four most common mechanisms to make covalent bonds?

Answer 6

alkylation
acetylation
phosphorylation
rearrangement

Question 7

Alkylation

Answer 7

adds an alkyl group

Question 8

acylation

Answer 8

add acyl groups

Question 9

Phosphorylation

Answer 9

addition of a nucleophile to make a phosphate

Question 10

What are the types of non covalent bonds?

Answer 10

ionic
ion-dipole
dipole
van der Waals
Aromatic interactions
chelation and complexation

Question 11

Most drugs bind and form one or more types of ?

Answer 11

noncovalent bonds

Question 12

Noncovalent bond strength?

Answer 12

0.5-10 Kcal/mol

Question 13

Are noncovalent reaction reversible?

Answer 13

yes

Question 14

As bond distance increases, bond attraction?

Answer 14

decreases

Question 15

If a functional group blocks binding site, what happens to the affinity of a drug and the receptor?

Answer 15

decrease it

Question 16

Ionic bonds

Answer 16

over the greatest distance, often initial recognition between the drug and the receptor

between acidic and basic functional groups or ionized acidic and quaternary ammonium functional groups

Question 17

Dipole interactions

Answer 17

occurs between functional groups with a partial charge separation

Question 18

Which two elements are more electronegative than C and H?

Answer 18

O and N

Question 19

Is there a dipole between C and H?

Answer 19

no

Question 20

Ion-dipole

Answer 20

bond between a full charge and a partial charge

Question 21

Dipole-dipole

Answer 21

bond between two partial charges

Question 22

Hydrogen bonds

Answer 22

the most common of dipole-dipole interactions
generally stronger than normal dipole-dipole bonds
hydrogen serves as a bridge between 2 electronegative atoms

Question 23

What is the ranking of best donor and acceptor using the XHY designation?

Answer 23

OHN>OHO>NHN~NHO

Question 24

When XHY is collinear, what occurs?

Answer 24

the strongest hydrogen bonds

Question 25

H bond formation helps with?

Answer 25

dissolution

Question 26

reinforced ionic bond

Answer 26

hydrogen bonds work with ionic bonds to enhance the overall bond strength

Question 27

What will an ionized functional group participate in? What will it not participate in?

Answer 27

Will- ionic bonds, ion-dipole bonds
won’t - dipole-dipole or pure H bond

Question 28

van der Waals Interactions

Answer 28

occur between non polar groups
highly distance specific
weak
no measurable dipoles
mutual polarization results in a dipole-induced dipole interactions

Question 29

What types of bonds can easily distribute electrons and form a dipole?

Answer 29

C-C and C-H

Question 30

Water molecules have what ability when they encounter a lipid surface?

Answer 30

to become highly ordered

Question 31

When two hydrophobic regions bind what happens to entropy?

Answer 31

it increases

Question 32

Why doesn’t every carbon group contribute to binding energy?

Answer 32

1. they may be electron donating
2. they may be in a polar region of a receptor and decrease the availability of lipid soluble functional groups
3. not every carbon atom meets steric dimensions
4. not every carbon atom is in the active site

Question 33

Charge transfer interactions

Answer 33

between electron rich and electron poor aromatic rings

Question 34

pi-pi stacking interactions

Answer 34

involves electron clouds of aromatic rings
similar to a van der Waals interaction but also involves polar movements

Question 35

cation-pi interactions

Answer 35

occur due to the attraction of a positively charged group to the electrons in a pi cloud of an aromatic ring

Question 36

chelation

Answer 36

when 2 distinct electron donating groups present on the same molecule, bind to a metal ion and form a ring structure

Question 37

metal complexation

Answer 37

whenever a metal ion interacts with a single atom but does not form a ring