An enhanced RNA-transport activity was observed in vitro from nuclei obtained from animals with cardiac hypertrophy as compared with that of sham-operated controls. The 100lOOg supernatants obtained from hypertrophic hearts stimulated the RNA transport from nuclei of sham-operated controls, and this stimulation was maximum with 40% supernatant. Ca2+-and nucleic acid-dependent ATPase and alkaline phosphatase activities, which may be involved in an energy-dependent transport, were high in nuclei from hypertrophic hearts, and the nuclei of sham-operated animals showed higher activities of these enzymes after incubation with supernatant from hypertrophic hearts, which stimulates the sham-operated animals.Transcriptional and post-transcriptional regulation and flow of genetic information from nucleus to cytoplasm in eukaryotic systems have been widely studied (Drews et al., 1968;Stevenin et al., 1969;Levitan & Webb, 1970;Lichtenstein & Shapot, 1976). By cell fusion and nuclear-transplantation experiments it was found that cytoplasmic factors regulate the expression of genes through feedback controls (Gurdon & Uehlinger, 1966;Harris, 1970). These feedback-control mechanisms operate not only at the transcriptional level but also at the post-transcriptional level. The availability of a cell-free system that can support nearly normal RNA processing and transport has made it possible to study the transport of RNA in vitro. In the present paper we report the occurrence of induced transport of RNA in vitro from the nuclei obtained from hypertrophic hearts compared with that from normal hearts. Schumm & Webb (1972 and Schumm et al. (1973) buffer for 18h at 40C with two changes, and 4.5mg of non-diffusable material was used along with 1 ml of incubation medium. After incubation the nuclei were pelleted by centrifugation at 100000 g (rav.5.35 cm) for 1 h, and RNA was extracted from the supernatant by the method of Penman (1966). The percentage of RNA was calculated from the radioactivity (c.p.m.) in the RNA released into the supernatant per mg of cytosolic protein. Enzyme activitiesATPase activity was assayed by the method of Tzagoloff (1970)

Protein derived from the oyster (Saccostrea cucullata) was hydrolyzed using protease from Bacillus cereus SU12 for isolation of antioxidant peptides. The oyster hydrolysate exhibited a strong antioxidant potential in DPPH (85.7±0.37%) followed by Hydrogen peroxide radical scavenging activity (81.6±0.3%), Hydroxyl radical-scavenging activity (79.32±0.6%), Reducing power assay (2.63±0.2 OD at 700nm). Due to the high antioxidant potential, hydrolysate was fractionated in Sephadex G-25 gel filtration chromatography. The active peptide fraction was further purified by UPLC-MS. Totally 7 antioxidant peptides were collected. Among 7 peptides (SCAP 1-7), 3 peptides (SCAP 1, 3 and 7) had highest scavenging ability on DPPH radicals. The amino acid sequence and molecular mass of purified antioxidant peptides (SCAP1, SCAP3 and SCAP7) were determined by Q-TOF ESI mass spectroscopy and structures of the peptides were Leu-Ala-Asn-Ala-Lys (MW=515.29Da), Pro-Ser-Leu-Val-Gly-Arg-Pro-Pro-Val-Gly-Lys-Leu-Thr-Leu (MW=1432.89Da) and Val-Lys-Val-Leu-Leu-Glu-His-Pro-Val-Leu (MW=1145.75Da), respectively. The unique amino acid composition and sequence in the peptides might play an important role in expression of their antioxidant activity. The results of this study suggest that oyster protein hydrolysate is good source of natural antioxidants.

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