We study infinitesimal gauge transformations of an equivariant noncommutative principal bundle as a braided Lie algebra of derivations. For this, we analyse general K-braided Hopf and Lie algebras, for K a (quasi)triangular Hopf algebra of symmetries, and study their representations as braided derivations. We then study Drinfeld twist deformations of braided Hopf algebras and of Lie algebras of infinitesimal gauge transformations. We give examples coming from deformations of abelian and Jordanian type. In particular we explicitly describe the braided Lie algebra of gauge transformations of the instanton bundle and of the orthogonal bundle on the quantum sphere S 4 θ .Date: March 2022. 1 7. Braided Hopf algebra of gauge transformations 38 7.1. Quantum principal bundle over quantum homogeneous space 40 8. Braided Hopf algebra gauge symmetry from twist deformation 42 8.1. Gauge transformations of twisted principal bundles 43 Appendix A. Proof of Proposition 4.14 52 References 54