Complex sentence: CO binds very well with iron in its +2 oxidation state; other heme-proteins, such as cytochrome P450, cytochrome c oxidase, catalase, and myoglobin may also become affected due to CO's toxic effects.
Split into simpler sentences: CO binds very well with iron in its +2 oxidation state. Other heme-proteins such as cytochrome P450, cytochrome c oxidase, catalase, and myoglobin may also become affected due to CO's toxic effects.