The Collaborative International Dictionary of English v.0.48:

Proteinaceous \Pro`te*i*na"*ceous\, a. (Physiol. Chem.)
   Of or related to protein; albuminous; proteid.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Albuminous \Al*bu"mi*nous\, Albuminose \Al*bu"mi*nose`\, a. [Cf.
   F. albumineux.]
   1. Pertaining to, or containing, albumin; having the
      properties of, or resembling, albumen or albumin; an older
      term now replaces by proteinaceous.
      [1913 Webster]

   2. proteinaceous; containing or composed of protein. --
      Al*bu"mi*nous*ness, n.
      [PJC]

WordNet (r) 3.0 (2006):

proteinaceous
    adj 1: relating to or of the nature of protein