I refer to the mail by T.S. Raju.
4-linked Gal is indeed not commonly found in normal mammalian type
O-/N-glycans. In both type 1 and 2 chains, the Gal itself is actually
3-linked ie -[3/4GlcNAc-3Gal]-. Known examples of 4-linked Gal (beta) are
i) the blood group P1 epitope Gal(alpha)1-4Gal(beta)-, and ii) as found in
the large multiantennary N-glycans from fish egg (JBC, 269, 8762-8771).
Further examples may be found by searching through the Carbank database.
4-Gal is more common in glycolipids as pointed out by J. Nash, occurring in
the globo series; and is widely found in structures from lower animals,
parasites, and bacteria.