No, it doesn't. His character stays true throughout the course of the play. In Act 1.2, Brutus present himself as a country-minded, extremely noble person by telling Cassius he will only act in the general good of Rome (lines 85-89). In Act 2.1, when Brutus decides to join the faction, he reinforces this idea that it's not personal (lines 10-12). In Act 3.2 he expresses his most noble notion by saying "as I slew my best lover for the good of Rome, I have the same dagger for myself when it shall please my country to need my death". This statement is resolved by his dying statement in Act 5.5, "Caesar, now be still. I killed not thee with half so good a will." In the end, Brutus was still acting for the good of Rome.