Mammalian odorant binding proteins

Odorant binding proteins (OBPs) pertain to one of the most abundant classes of proteins found in the olfactory apparatus. OBPs are a sub-class of lipo calins, defined by their property of reversibly binding volatile chemicals, that we call 'odorants'. Numerous sequences of OBPs are now available, der ived from protein sequencing from nasal mucus material, or from DNA sequenc es. The structural knowledge of OBPs has been improved too in recent years, with the availability of two X-ray structures. The physiological role of O BPs remains, however, essentially hypothetical, and most probably, not link ed to a function of odor transport. The present knowledge on OBP biochemist ry, sequence and structure will be examined here in relation to the differe nt functional hypotheses proposed for OBPs. (C) 2000 Elsevier Science B.V. All rights reserved.