Dear Martins

the homodimerization can be induced from different factors and not only inter molecular s-s bonds. For example human Cu,Zn sod1 is a dimer and also if it contain cisteines those are not directly responsible for the dimerization that happen through hydrophobic interactions. A monomeric mutants if Cu, Zn was designed (Phe50Glu, Gly51Glu, Val148Lys, Ile151Lys) performing mutations that do not involve cisteines but just insert charged aa to destroid the hydrophobic interaction.

https://onlinelibrary.wiley.com/doi/abs/10.1002/%28SICI%291520-6343%281999%295%3A5%2B%3CS33%3A%3AAID-BSPY4%3E3.0.CO%3B2-E?af=R

good luck

Mamuele

Dimeric interfaces are often complementary, involving specific hydrophobic and/or hydrophilic interactions. Despite their non-covalent nature, the latter can sometimes achieve picomolar affinities. Please check the following review for several examples:

https://www.researchgate.net/publication/8214828_The_power_of_two_Protein_dimerization_in_biology

Dear Martin,

As previously mentioned, oligomerization doesn't necessary involved a covalent bound.

You can analyze the sequence of your protein a bit deeper in looking if there are homologous protein of known structure. Thus, you might be able to understand more about the oligomerisation process and, may be, identify residues that could be good candidates for dimerization (using per example blastp against pdb, InterPro, pCoil).

good luck,

A.

E. coli phosphofructokinase homodimerizes and then homotetramerizes without any cystine bonds forming. I never published this work, but did some ultracentrafugation studies 20 years ago in which I was studying the dimerization and tetramerization constants of some versions of E.coli PFK where I had made mutations that potentially affected the interface across the dimer/dimer surface. No cysteine pairs at all, but quite strong interaction.