Partial purification of HLAMP-1 provides direct evidence for the multicomponent nature of the particulate matrix associated with cardiac mesenchyme formation.

H-LAMP-1 is a 283 kDa protein that is involved in the transformation of endothelial cells into mesenchyme within the AV canal and proximal outflow tract of the heart. This protein is part of the particulate matrix that has been suggested to be composed of multicomponent complexes that have been termed cardiac adherons. However, to date no direct evidence has been provided that these proteins are complexed into an adheron-like particle. This report provides the first such evidence by showing that purification of hLAMP-1, under gentle conditions, results in the isolation of multiple bands of similar molecular weight within the fractions that contain anti-hLAMP-1 activity.