POLYOL ACCUMULATION IN IN VITRO SYSTEMS OF BOMBYX EGGS

The mechanism of polyol accumulation in diapausing Bombyx eggs, conversion of [6-¹⁴C] glucose-6-phosphate into polyols and other neutral sugars was investigated in in vitro reaction systems. When a crude homogenate or a press juice of the eggs was incubated with [6-¹⁴C]glucose-6-P, the labelled trehalose, sorbitol and glycerol accumulated in the reaction mixture. In the press juice incubation system of developing eggs at day 1, ¹⁴C-sorbitol was detected in appreciable amounts, but it decreased rapidly with the development of the embryos. When the press juice was prepared from eggs in diapause, the formation of ¹⁴C-sorbitol was 3–5 times greater in eggs at early stages (day 2 to day 4) than in developing eggs.     

CYCLIC NUCLEOTIDE-DEPENDENT PROTEIN KINASES FROM SILKWORM EGGS: OCCURRENCE OF TWO CYCLIC NUCLEOTIDE-DEPENDENT PROTEIN KINASES, CHANGES IN THEIR ACTIVITIES AND LEVELS OF CYCLIC NUCLEOTIDES DURING DEVELOPMENT OF THE EGGS

Two cyclic nucleotide-dependent protein kinases, designated as protein kinase-I and -II, were obtained from the eggs of the silkworm, Bombyx mori . Protein kinase-I is highly dependent on cGMP, whereas protein kinase-II is dependent on cAMP. In developing non-diapause eggs, the level of cyclic nucleotide-dependent protein kinase activity is quite high but that in the diapause eggs is not. The developmental changes in the two protein kinases and the level of cyclic nucleotides were also studied during the development of the eggs.     

Tea leaf peroxidase--Isolation and partial purification

Tea leaf peroxidase occurred as the insoluble form in a homogenate.A large part of the peroxidase from tea leaves was solubilizedin a homogenate by adding Tween-80. After fractionation by 0.3saturation with (NH₄)₂SO₄ and filtration of the homogenate througha Sephadex G-25 column, specific activity of the peroxidasein the effluent increased about 25 times. Crude peroxidase wasfractionated into six components; A-l, A-2, B-l, B-2, B-3 andC, by DEAE- and CM-cellulose column chromatography. The fractionsshowed different mobilities on disc gel electrophoregram atpH 4.2. An isoelectric focusing experiment indicated that pivalues of the A-l and A-2 components are 5.4 and 5.0, repsectively. ¹ Present address: National Institute of Agricultural Science,Ministry of Agriculture and Forestry, Nishigahara, Kita-ku,Tokyo, Japan. (Received October 19, 1970; )