  Cosmic infrared emission and absorption spectra often carry a well-defined
and invariant 6.2 micron band that has been proposed to emanate from very small
dust grains that may carry polyaromatic hydrocarbons. Hemoglycin, a
well-defined polymer of glycine that also contains iron, has been found in
meteorites of the primordial CV3 class and therefore originated in the solar
protoplanetary disc. In approximate calculations, the principal amide I
infrared absorption band of hemoglycin is at 6.04 microns. Hemoglycin, an
antiparallel beta sheet structure with two 11-mer glycine chains, has an exact
structural analog in antiparallel poly-L-lysine beta sheets which in the
laboratory have an absorption peak at 6.21 microns. This wavelength
coincidence, the demonstrated propensity of hemoglycin 4.9nm rods to form
accreting lattice structures, and its proven existence in the solar
protoplanetary disc strongly suggest that the cosmic 6.2 micron emission and
absorption could be from small grains that are hemoglycin lattices or
shell-like vesicles carrying internal organic molecules of various types.
Calculated hemoglycin ultraviolet absorptions associated with iron in the
molecule match the observed ultraviolet extinction feature at nominal 2175
Angstroms.
