Studies on Carotenoprotein In Aquatic Animals : Ill. The Relationship between Blue and Purple Carotenoproteins in Crayfish (Cambarus clarkii) Exoskeleton

アメリカザリガニ甲殼から得た青色カロチノプロテイン(以下Bと略記)と紫色カロチノプロテイン(以下Pと略記)のアポ蛋白質の分析結果より,それぞれのアポ蛋白質は異ったサブユニットで構成されていることを明らかにした.

約10万の分子量をもつBは尿素の存在により分子量約5万のPに変化する。Bは,ある条件下で,補欠分子族のカロチノイド含量が減少することにより,Pおよびカロチノイドを含まない蛋白質に解裂し,最終的には縮合して赤色カロチノプロテインを生ずる.甲殼内においてもBとPは相互変換が起りうると考えた.

From the results of the electrophoretic and the amino acid determinations, the apoproteins prepared from blue carotenoprotein (B) and purple carotenoprotein (P) of the crayfish (Cambarus clarkii) exoskeleton were found to consist of different subunit.

P, molecular size about 5×104, was derived from B with the molecular size about 105 by urea treatment. B was able to dissociate to P and carotenoid-free proteins due to the decrement of the prosthetic group carotenoid content under the certain conditions, these thereafter resulted by aggregation in a red carotenoprotein (R) with lower carotenoid content.

The possibility of conversion among three carotenoproteins in the exoskeleton under certain conditions was discussed.