Structural mapping of rabbit muscle phosphofructokinase. Distance between the adenosine cyclic 3',5'-phosphate binding site and a reactive sulfhydryl group.

Published

Journal Article

The cAMP binding site of rabbit muscle phosphofructokinase has been labeled with the fluorescent molecule 5'-(p-fluorosulfonylbenzoyl)-2-aza-1,N6-ethenoadenosine. The most reactive sulfhydry- group of this modified enzyme, which is catalytically active, has been labeled with 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole and with N-]4-(dimethylamino)-3,5-dinitrophenyl]maleimide. The calculated distances between the cAMP binding site and the most reactive sulfhydryl group, as determined by resonance energy transfer measurements, are 31 and 26 A, respectively, for the two sulfhydryl group labels. Both steady-state and fluorescent -ifetime techniques were used to measure the energy transfer efficiencies in 50 mM potassium phosphate (pH 8.0) and 1 mM ethylenediaminetetraacetic acid, and a value of 2/3 was assumed for the donor-acceptor orientation factor. If the difference in calculated distances is attributed to a difference in the orientation factor for the two donor-acceptor ,airs, the actual distance between the cAMP ligand binding site and the most reactive sulfhydryl group on phosphofructokinase is shown to be 28 +/- 6 A.

Full Text

Duke Authors

Cited Authors

  • Craig, DW; Hammes, GG

Published Date

  • January 22, 1980

Published In

Volume / Issue

  • 19 / 2

Start / End Page

  • 330 - 334

PubMed ID

  • 6243478

Pubmed Central ID

  • 6243478

International Standard Serial Number (ISSN)

  • 0006-2960

Digital Object Identifier (DOI)

  • 10.1021/bi00543a013

Language

  • eng

Conference Location

  • United States