Barley lipid transfer protein, LTP1, contains a new type of lipid-like post-translational modification.
In plants a group of proteins termed nonspecific lipid transfer proteins are found. These proteins bind and catalyze transfer of lipids in vitro, but their in vivo function is unknown. They have been suggested to be involved in different aspects of plant physiology and cell biology, including the formation of cutin and involvement in stress and pathogen responses, but there is yet no direct demonstration of an in vivo function. We have found and characterized a novel post-translational modification of the barley nonspecific lipid transfer protein, LTP1. The protein-modification bond is of a new type in which an aspartic acid in LTP1 is bound to the modification through what most likely is an ester bond. The chemical structure of the modification has been characterized by means of two-dimensional homo- and heteronuclear nuclear magnetic resonance spectroscopy as well as mass spectrometry and is found to be lipid-like in nature. The modification does not resemble any standard lipid post-translational modification but is similar to a compound with known antimicrobial activity.
Lindorff-Larsen
K
K
Department of Yeast Genetics, Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-2500 Copenhagen Valby, Denmark.
Lerche
M H
MH
Poulsen
F M
FM
Roepstorff
P
P
Winther
J R
JR
D000596:Amino Acids / Q000737:chemistry; D001224:Aspartic Acid / Q000737:chemistry; D002241:Carbohydrates / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry; D004952:Esters / Q000737:chemistry; D006031:Glycosylation; D001467:Hordeum / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008055:Lipids / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008956:Models, Chemical; D008958:Models, Molecular; D010455:Peptides / Q000737:chemistry; D010940:Plant Proteins / Q000737:chemistry*; D011499:Protein Processing, Post-Translational; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry*; D029701:Saccharomyces cerevisiae Proteins; D013696:Temperature; D013997:Time Factors; D014357:Trypsin / Q000737:chemistry
D000596:Amino Acids; D002241:Carbohydrates; D002264:Carboxylic Acids; D004952:Esters; D008055:Lipids; D010455:Peptides; D010940:Plant Proteins; D029701:Saccharomyces cerevisiae Proteins; D001224:Aspartic Acid; C094972:LTP1 protein, S cerevisiae; D017027:Protein Tyrosine Phosphatases; D014357:Trypsin