Incorporation of low molecular weight molecules into alpha(2)-macroglobulin by nucleophilic exchange.
Published
Journal Article
alpha(2)-Macroglobulin (alpha(2)M) is a proteinase inhibitor that functions by a trapping mechanism which has been exploited such that the receptor-recognized, activated form (alpha(2)M( *)) can be employed to target antigens to antigen-presenting cells. Another potential use of alpha(2)M( *) is as a drug delivery system. In this study we demonstrate that guanosine triphosphate, labeled with Texas red (GTP-TR) formed complexes with alpha(2)M( *) following activation by proteolytic or non-proteolytic reactions. Optimal incorporation occurred with 20 microM GTP-TR, pH 8.0 for 5h at 50 degrees C. NaCl concentration (100 or 200 mM) had little effect on incorporation at this pH or temperature, but was significant at sub-optimum temperature and pH values. Maximum incorporation was 1.2 mol GTP-TR/mol alpha(2)M( *). PAGE showed that 70-90% of the GTP-TR is bound in a SDS/2-mercaptoethanol resistant manner. Guanosine, adenosine, and imidazole competed with GTP-TR to form complexes with alpha(2)M( *).
Full Text
Duke Authors
Cited Authors
- Bond, JE; Cianciolo, GJ; Pizzo, SV
Published Date
- June 1, 2007
Published In
Volume / Issue
- 357 / 2
Start / End Page
- 433 - 438
PubMed ID
- 17428443
Pubmed Central ID
- 17428443
International Standard Serial Number (ISSN)
- 0006-291X
Digital Object Identifier (DOI)
- 10.1016/j.bbrc.2007.03.151
Language
- eng
Conference Location
- United States