what effect will a positive charge, brought in proximity of an aspartate side chain in a protein, will have on its pka? 1. the pka of the aspartate residue will remain the same. 2. the pka of the aspartate residue will decrease. 3. the pka of the aspartate residue will increase. 4. there will be a water bridge established between the positive charge and the aspartate residue. group of answer choices