Plant cells contain proteins, called lipid transfer proteins (LTP) [1,2,3], which are able to facilitate the transfer of phospholipids and other lipids across membranes. These proteins, whose subcellular location is not yet known, could play a major role in membrane biogenesis by conveying phospholipids such as waxes or cutin from their site of biosynthesis to membranes unable to form these lipids.

Plant LTP's are proteins of about 9 Kd (90 amino acids) which contain eight conserved cysteine residues all involved in disulfide bridges, as shown in the following schematic representation.

                     +-----------------------+
                     |    +------+           |
                     |    |      |           |    ****************
                    xCxxxxCxxxxxxCCxxxxxxxxCxCxxxxxxxxxxxCxxxxxxCxx
                                  |        |             |      |
                                  +--------|-------------+      |
                                           +--------------------+

'C': conserved cysteine involved in a disulfide bond.
'*': position of the pattern.