Introduction of negative charges to a crosslinked hemoglobin: lack of effect on plasma half time.

Intramolecularly crosslinked hemoglobins do not dissociate into alpha 1 beta 1 dimers. As a result, they escape glomerular filtration and have plasma half times of 4 hours. This value is shorter than for albumin (5.2 hours) with similar molecular weight but higher negative charge. The present study was done to determine if increased negative charge on a hemoglobin covalently crosslinked with bis (3,5-dibromosalicyl) sebacate would lengthen its plasma half time. Negative charge was introduced by acylation with succinic anhydride. The product had a higher negative charge; however, plasma half time was not increased. A larger fraction of the succinylated material was excreted in the urine suggesting molecular instability.