Time profile of hemin aggregation: an analysis.

The status of hemin, whether monomeric or aggregated, appears to be a key factor in deciding its biological activity. The molecular basis for the tendency of hemin to aggregate and the factors that regulate it are not yet fully understood. We have investigated the time profile of aggregation of hemin in aqueous solutions and the effect of temperature on the process of aggregation. Aggregation increases with increase in temperature. The time profile data, as monitored by change in absorbance at 398 nm, fits a nonlinear equation with three time constants, suggesting a possibility of three processes. Interestingly, the variation of these three time constants with temperature are different.