Aggregation analysis of Con A binding proteins of human seminal plasma: a dynamic light scattering study

Concanavalin A (Con A) binding fraction of human seminal plasma is vital as it shows decapacitating activity and contains proteins which have critical roles in fertility related processes. Con A binding proteins were isolated by lectin affinity chromatography. These proteins form high molecular weight aggregates at near physiological pH (7.0) as inferred by gel filtration. Aggregation analysis was performed by dynamic light scattering (DLS). DLS analysis was also performed at different pH values and in presence of various additives including NaCl, EDTA, cholesterol and sugars, such as d-glucose, d-fructose and d-mannose to identify their effect on aggregation size. The results indicate that degree of aggregation was highly reduced in presence of d-fructose, EDTA and at lower and higher pH values as depicted by lowering of hydrodynamic radii. This aggregation behaviour might be decisive for fertility related events with a suggestive role towards inhibition of premature capacitation.