Coat a 12-cup Bundt pan with nonstick cooking spray, then dust with a little flour.
Set aside 1/4 cup of cake mix. Beat remaining cake mix and butter in a large bowl of an electric mixer on medium-high speed for 1 minute, until crumbly.
Beat in sour cream, eggs, lemon juice, and lemon peel until blended.
Toss blueberries in the reserved cake mix to coat them. Fold gently into batter.
Spread batter evenly into prepared pan. Bake for 50 to 55 minutes.
Cool in pan for 30 minutes, then remove to a wire rack to continue cooling completely.