CDNA-INFERRED AMINO-ACID-SEQUENCE OF A C-PROTEIN, A HEPARIN-BINDING, BASIC SECRETION PRODUCT OF THE TUBULAR ACCESSORY SEX GLANDS OF THE MEALWORM BEETLE, TENEBRIO-MOLITOR

C proteins represent one of the four major protein groups secreted by the tubular accessorv glands of male mealworm beetles (Tenebrio molito r). Thev are basic proteins with an apparent molecular mass of 21.9 kD a. In this paper we present the deduced amino-acid sequence of two, al most identical C proteins, termed C1 and C2. The C proteins contain a consensus sequence for a heparin-binding site, and thev are efficientl y purified from accessory gland homogenates by heparin-affinitv chroma tography. No sequence resemblance was found with other proteins in the databases, but their high avidity for heparin suggests a possible inv olvement of the C proteins in sperm capacitation.