Some properties of the main protein of honeybee (Apis mellifera) royal jelly

Abstract

Royal jelly (RJ) was separated by ultracentrifugation (245000 × g for 5 h at 6°C) into three physically distinct fractions with different distribution of its components (proteins, sugars and fatty acids): yellowish fluid supernatant (61% w/w of RJ), yellowish-brown gelatinous sediment (32% w/w) and white nearly solid sediment (7%, w/w). Ultracentrifugation of the solvated gelatinous fraction was a suitable method for preparation of MRJP1, the most abundant protein of RJ in the form of gel. MRJP1 was present in RJ in different forms: a monomer (55 kDa), oligomeric subunit (ca. 420 kDa), and water-insoluble aggregates in sediment after its interaction with fatty acids. The oligomeric MRJP1 was well soluble in water and at concentrations of 30 to 50% (w/w) formed a stiff gel. It is suggested that MRJP1 is albumin-like protein. An interesting feature of the oligomeric form of MRJP1 is its ability for self-assembly in water solutions.