what causes different links within a protein chain ?

[kate26]

so i came across a question asking about what variable group within a protein would be likely to rely on dispersion forces to be attracted to neighbouring sections and i was kinda like whaaaa?

so i was hoping someone would be able to help out with what causes the different bonding within the tertiary structure of protein.

any help will be greatly appreciated

cheers

[Martoman]

Usually its the interactions of the Z group with other Z groups.

[kate26]

yeaaah i know that i was kinda hoping to find out what atoms exactly were involved ... ?

[Martoman]

Disulfide == S

Polar bonds == O-H or COOH

Dispersion == CH3, CH2

[kate26]

righteo thanks

[m@tty]

Well the R group can have basically anything on it. And it is the interaction on these side groups which constitutes the tertiary structure of a protein.

Something which will only have dispersion will be non-polar; I'd say a methyl group.

Another kind of bonding is covalent; this can be di-sulfide, for example, where two S-H groups combine to form an S-S link. There are probably other kinds of covalent bonding possible between side chains, but this is the only example I can think of presently.

There's also Hydrogen bonding. Which could be between carbonyl groups(C=O) and hydroxyl groups(O-H) or Amine groups(N-H₂)

Finally(I think) there can be ionic interaction. This happens between a negatively charged species and a positively charged one. A possible combination could be the deprotonated carboxyl group(COO^-) and the cationic amine group(NH₃⁺).

I think that is basically it.

[kate26]

thanks that really clears it up