The postprandial hypertriglyceridaemia (PHT) rabbit, developed as a new animal model of metabolic syndrome, is characterized by PHT, central obesity and glucose intolerance. For detailed investigation of lipid metabolism characteristics in PHT rabbit, the plasma levels of apolipoproteins A-I, B, C-II, C-III and E were measured. Movements of apolipoproteins B100 and B48 were investigated using sodium dodecyl sulphate-polyacrylamide gel electrophoresis to determine whether postprandially increased triglyceride is exogenous or endogenous. The level of apolipoproteins A-I, B, C-II and E were increased in PHT rabbit after feeding. Apolipoproteins B100 and B48 were detected in the plasma fraction of d , 1.006 g/mL of the PHT rabbit. The postprandial increase in apolipoprotein B in the PHT rabbit reflects a numerical increase in lipoprotein particles in the blood; the increase in apolipoproteins C-II and E suggests some disturbance in lipoprotein catabolism. Apolipoprotein B48 was detected postprandially in PHT rabbits. These results suggest that delayed catabolism of exogenous lipids caused the retention of chylomicron remnants in the blood. Results also suggest that activities of the lipolytic enzyme lipoprotein lipase and hepatic triglyceride lipase were deficient and that the hepatic uptake of exogenous lipoproteins was delayed in the PHT rabbit. Especially, for examining remnant hyperlipoproteinaemia in humans, PHT rabbit is an excellent animal model for hypertriglyceridaemia research. Ischaemic heart disease is closely related to the plasma cholesterol (CHO) level. However, results of recent studies have demonstrated that not all patients developing ischaemic heart disease have hypercholesterolaemia 1 and that elevated levels of serum triglycerides (TG) increase the risk of ischaemic heart disease.2,3 Furthermore, metabolic syndrome, a condition in which central obesity is complicated by multiple risk factors of atherosclerosis (hypertriglyceridaemia, glucose intolerance and hypertension), has recently been suggested to increase the risk of ischaemic heart disease. From the Watanabe heritable hyperlipidaemic (WHHL) rabbit, Tomoike et al. of the Yamagata University Faculty of Medicine selectively bred the WHHL-TGH (triglyceride-high) rabbit, in which serum CHO and TG levels were both high, and the WHHL-TGL (triglyceridelow) rabbit, in which the CHO level was high but the TG level was normal.4 Tomoike et al. also developed the postprandial hypertriglyceridaemic (PHT) rabbit model, which showed normal serum TG and CHO levels during fasting, but an abnormally high level of TG alone postprandially. 4 The PHT rabbit, which showed a high postprandial TG level, was derived from the mutant F2 hybrid by crossbreeding between the Japanese White (JW) rabbit and the WHHL-TGH rabbit.The PHT rabbit was derived from the WHHL-TGH rabbit by eliminating the factor of hypercholesterolaemia and selecting individuals who showed PHT. Actually, the PHT rabbit strain is considered to be polygenic.5 Expected to be a novel animal m...

An Aspergillus oryzae RIB40 (NBRC100959) α-glucosidase (designed as AgdB)gene (agdB) was expressed at high levels in an A. oryzae host by self-cloning. The obtained transformant (MIBA1002) produced intracellular and extracellular α-glucosidase at levels 3-and 10-fold higher, respectively, than the parent host strain. The base sequence of agdB consisted of a 3036-kb structural gene containing three introns and encoding 963 amino acids, and the linear sequence thus obtained from these amino acids was identical to A. oryzae RIB40 unknown protein BAE64257.1. The amino acid sequence had 72% and 51% homology to α-glucosidase B from Aspernillus nidulans and Acremonium implicatum, respectively, which exhibit transglycosylation activity. The sequence has conserved residues specific to glucosyl hydrase family 31 (GH31) α-glucosidases. Tyr296 present in the β→α Loop1 in GH31 is important for transglycosylation. The enzyme produced 2.2% isomaltose, 0.4% maltotriose, and 0.3% kojibiose from 20% maltose substrate. This is the first report of the transglycosylation activity of α-glucosidase B cloned in A. oryzae (unknown protein BAE64257.1).