We have prepared a nuclear matrix fraction from maize seedlings and st
udied its protein composition. Proteins were characterized by immunobl
otting analysis, two-dimensional gel fractionation and two-dimensional
peptide mapping. Most of them were found to belong to the group of IF
-lamina proteins, as has been shown for the matrix proteins from anima
ls. One of these proteins was further classified as the maize version
of lamin C since it possessed an isoelectric point in the range charac
teristic for lamin C from animals, cross-reacted with anti-lamin c ant
iserum and its two-dimensional peptide map contained most of the spots
characteristic of the map of mouse Earlich ascite tumor lamin C. Unli
ke animal lamins (proteins of molecular masses in the range of 60-75 k
Da), the maize lamin C possessed a molecular weight of 42 kDa. A group
of proteins possessed molecular masses in the 65- to 75-kDa range and
isoelectric points similar to that of animal lamin B. In addition, th
eir 2D peptide maps revealed considerable similarity with the map of l
amin B from avian erythrocytes. However, these proteins do not resembl
e lamin B from EAT cells neither immunologically nor by tryptic peptid
e mapping. Two proteins of our preparation are not lamin-like. The try
ptic peptide maps of the proteins reveal similarity with some animal p
roteins that bind DNA tightly.