"It has been postulated the dry heat processing of proteins produces a
new lysine linkage which is either not digestible by enzymes or is so
slowly digested that lysine enters the blood stream too late to
participate with the rest of the assimilated amino acids in tissue
formation."

More severe heat damage to proteins results when moist heat is used.
When reducing sugars (e.g. glucose) are present, true destruction of
amino acids has been repeatedly corroborated. This destruction may
account for a loss of 50% of the lysine, arginine, tryptophan, and
histidine content.

Reference:
"Present status of heat-processing damage to protein foods". Nutrit.
Rev. 8: #7, 193-196, July 1950

Thank you Wes, for these references. Keep 'em coming. The story fits
with the findings that "Nonenzymic glycosylation of proteins by reducing
sugars leads to the formation of advanced glycosylation end products
(AGEs, [or Maillard Molecules])...by interfering with functionally
important lysine groups and amino-terminal amines."

Palinski, et al, Immunological evidence for the presence of advanced
glycosylation end products in atherosclerotic lesions of euglycemic
rabbits. Arteriosclerosis, Thrombosis, and Vascular Biology Vol 15, No 5
May 1995.

My best, Ellie