Characterizing artificial blood substitutes and testing the Monod two-state model using heterodyned phase-grating spectroscopy

Summary form only received as follows: The development of cross-linked Hb artificial blood substitutes is an area of much growth and attention. Where donated blood can be stored for up to three weeks, artificial blood can be stored indefinitely. The problem of disease transmission is negligible. Moreover, these blood substitutes can act as drug-delivery agents as well as having the capacity to deliver oxygen to cancerous sites and aid in photodynamic therapy techniques. In previous work the authors have characterized Hb and Mb using time-resolved phase grating spectroscopy. Recently they have increased the sensitivity of their experiment by implementing heterodyne detection using a diffractive optic. This has allowed them to detect the extremely small changes in structure of these blood substitutes and aid-in their development and understanding. The advent of these artificial blood substitutes also opens up a new venue by which to study energy transduction in biomolecules. This puts the authors in a unique position to test the predictions of the Monod two-state model. By varying the sites of cross-linking they have tested the Monod two-state model for Hb. New results characterizing these cross-linked Hb and probing the validity of the Monod two-state model are shown.