HLAMP--a conjugate of hippuryllysine and AMP which contains a phosphoamide bond--stimulates chemotaxis in Dictyostelium discoideum.
A conjugate of hippuryllysine (HP) and adenylic acid was synthesized and purified. The structure of the conjugate, hippuryllysyl(N-epsilon-5'-phospho)adenosine (HLAMP) was established using 31P nuclear magnetic resonance, UV spectroscopy, acid/base lability, and enzyme digestion with AMP deaminase, alkaline phosphatase, 5'-nucleotidase, and a phosphoamidase activity recently identified in Dictyostelium discoideum. The results indicate that HLAMP contains a phosphoamide bond between the phosphate of AMP and the epsilon amino group of HL. Employing a microdroplet assay to assess chemotactic activity, HLAMP was found to be a potent chemoattractant of 7-h developing amoebae of D. discoideum. Other conjugates, including lysine-AMP (LAMP), tuftsin-AMP (TAMP) and avidin-AMP (AVAMP), as well as the degradation products of HLAMP (HL, AMP, and lysine) exhibited no chemotactic activity. The molecular structure of HLAMP is compared to that of other known chemoattractants of the cellular slime molds, and possible chemotactic receptors for HLAMP are considered.
Department of Biostructure and Function, University of Connecticut Health Center, School of Dental Medicine, Farmington 06032.
E F
EF
Rossomando
J
J
Hadjimichael
B
B
Varnum-Finney
D R
DR
Soll
D002633:Chemotaxis / Q000187:drug effects*; D004023:Dictyostelium / Q000187:drug effects / Q000502:physiology*; D006867:Hydrolases / Q000378:metabolism; D013329:Structure-Activity Relationship
D006867:Hydrolases; C049021:phosphoamidase