Systems containing highly-charged polyelectrolytes and proteins have many applications, including protein separations, developing polyelectrolytes to immobilize enzymes, and as model systems to understand biologically relevant protein-polysaccharide interactions. Engineering these systems requires an understanding of the conformational behaviour of polyelectrolytes in solution. While there have been extensive studies on dilute polyelectrolyte solution properties, very little is known about the influence of stereochemistry on polyion conformation. In this work, we study sulfonated polystyrenes with unique stereochemical structure: (a) atactic polystyrene (aPS), in which the phenyl groups are located randomly on both sides of the polymer backbone chain, and (b) isotactic polystyrene (iPS), in which the phenyl groups are located on the same side of the polymer backbone chain. In the gel state, isotactic polystyrene has a 31 helix local structure, while atactic polystyrene forms no helix, but if seen from a tryad point of view, the polyion appears to show syndiotacticity. Using static and dynamic light scattering, we determine the sizes and intermolecular interactions between the polyions as a function of salt concentration. Our small angle X-ray scattering results show that sodium salt of sulfonated isotactic polystyrene (NaiPSS) has smaller persistence length than sodium salt of sulfonated atactic polystyrene (NaaPSS), indicating that the local structure affects the chain stiffness. We study the variation of the persistence length with ionic strength. Furthermore, we investigate Hofmeister effects of the added salt to provide insight into the importance of hydrophobic interactions. The experiment results are complemented with simulations on an idealized, minimal polyelectrolyte model with anisotropic interactions, which can form helical structures. All these results present a clear picture of the conformation of the polyelectrolytes with different stereochemistry in solution and also the effect of stereochemistry on the electrostatic and hydrophobic forces of the polyelectrolytes in solution.