title: Quantitative Analysis of Apisin, a Major Protein Unique to Royal Jelly.
abstract: Apisin, a protein that is unique to royal jelly (RJ), is known to compose the greater part of the RJ proteins and to exist as a heterooligomer containing major royal jelly protein 1 and apisimin. However, few reports on the methods for quantifying apisin have been published. Thus, we attempted to quantify apisin using HPLC, a widely used analytical technique, as described below. Isoelectric precipitation and size-exclusion chromatography were used to obtain the purified protein, which was identified as apisin by SDS-PAGE and LC-MS analyses. The purified apisin was lyophilized and then used to generate a calibration curve to quantify apisin in RJ. The apisin content was fairly constant (i.e., 3.93 to 4.67 w/w%) in natural RJ. This study is the first to describe a simple, standardized method for quantifying apisin using HPLC and suggests that apisin can be used as a benchmark for future evaluations of RJ quality.
authors.affiliation: Nagaragawa Research Center, API Co., Ltd., 692-3 Nagara, Gifu 502-0071, Japan.
authors.forename: Takako
authors.identifier: 0000-0003-4154-7080
authors.initials: T
authors.lastname: Furusawa
authors.affiliation: Nagaragawa Research Center, API Co., Ltd., 692-3 Nagara, Gifu 502-0071, Japan.
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Arai
authors.affiliation: Nagaragawa Research Center, API Co., Ltd., 692-3 Nagara, Gifu 502-0071, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Kato
authors.affiliation: Nagaragawa Research Center, API Co., Ltd., 692-3 Nagara, Gifu 502-0071, Japan.
authors.forename: Kenji
authors.identifier: 0000-0001-7925-4561
authors.initials: K
authors.lastname: Ichihara