Studies on vitellin of water wolf spider Pirata piraticus.
真水狼蛛Pirata piraticus卵黄蛋白的研究

Vitellin was isolated and purified from the eggs of a water wolf spider, P. piraticus .The final preparation is existed only in reproducing females as judged by polyacrylamide gel electrophoresis and immunodiffusion method. The vitellin was defined as glycolipoprotein. The isoelecctric point is pH 6.7 7.5. The amino acid composition shows a high content of aspartic acid and glutamic acid, and low content of sulfur containing amino acid, methionine and cysteine. Molecular weight of the vitellin is 255 kD and the molecule is composed of four subunits with molecular weight of 84 kD, 69 kD, 63 kD and 49.8 kD, respectively. During embryonic development of the spider, the content of vitellin in embryos decreases rapidly. Suitable temperature and mixed feed will help the development of the ovary and the synthesis of the vitellin. Ovary may be the synthetic position of vitellin. The mechanisms how temperature and food affecting the reproduction of the spider are discussed by comparing the vitellin content of ovary and diameter of eggs.