Going through the following articles may be useful.

https://scholar.google.com.pk/scholar?hl=en&as_sdt=0,5&as_vis=1&qsp=1&q=optimization+of+antibody+production+systems&qst=br

https://info.gbiosciences.com/blog/optimize-antigen-and-antibody-concentration-for-western-blots?hs_amp=true

https://www.abcam.com/protocols/cross-linking-chromatin-immunoprecipitation-x-chip-protocol - This protocol may help. It is mentioned that 1-10 ug of antibody often works per 25 ug of DNA (that is measured after sonication is done). As you are willing to test the presence of a protein in the experimental lysate, western blot can be a better choice.

Titrate the amount of antibody required by performing a ChIP experiment using a range of antibody concentrations. As Avik mentioned, the amount of antibody required by ChIP generally ranges from 1 to 10 µg of antibody for every 25 µg of chromatin. https://docs.abcam.com/pdf/chromatin/A-beginners-guide-to-ChIP.pdf