The primary structure of spinach-leaf phospholipid-transfer protein.

The complete amino acid sequence phospholipid-transfer protein isolated from spinach leaves has been determined. The primary structure of the spinach protein was elucidated by analyses by HPLC of cyanogen bromide fragments and peptides obtained by tryptic digestions. The single polypeptide chain of the spinach protein consists of 91 amino acid residues. The protein contains six cysteines whereas phenylalanine and glutamine are absent. The present data, which are the first to be obtained with a phospholipid-transfer protein from a photosynthetic tissue, are compared to the amino acid sequences determined with plant and animal proteins involved in the intracellular transport of hydrophobic compounds.