Protein disulphide isomerase (PDI) is an enzyme that catalyses disulphide-bond formation in protein to maintain the native conformation, either through redox or isomerization reactions. Few PDI’s have been isolated from various organism such as mammalian livers, plants, green algae and Saccharomyces cerevisiae. Disruption of the PDI in S. cerevisiae is haplo lethal indicating that the product of this gene is essential for viability. PDI consist of 1590 pb, but the essential domain on PDI gene have not been known complete. To study caracteristic PDI protein domains, in this research was undertaken construstion PDI mutant on S. cerevisiae. In vitro mutagenesis was carried out using hidroxilamin (HA) as mutagen. Recombinant plasmid were constructed by ligation of mutated DNA fragment (758 pb) into a vector (6300 pb) using T4 DNA ligase. The result showed some mutants were lethal, indicated that b and b’ domains are essential for PDI on S. cerevisiae. Few mutants poorly growth, and the other showed well growth.
Indonesia is known as a country rich in species of seaweed. The most important components of seaweed are iodine and dietary fiber. Eucheuma cottoni is one species of seaweed that can be used as a source of iodine and dietary fiber. Iodine deficiency can cause several diseases also known as IDD (Iodine Deficiency Disorder), while deficiency of dietary fiber can cause some degenerative diseases. This research is taken to develop the utilization of Eucheuma cottoni as an ingredient in the making of jam and “dodol” (Indonesian traditional snack food).
The best ratio of seaweed and sugar for jam production was 37:63, while the best ratio of seaweed and glutinous flour in making dodol was 5:2. The addition of seaweed on jam and dodol formula increased their iodine and dietary fiber contents. The iodine content of jam and dodol was and Ã‚Âµg/g, respectively. The dietary fiber content of jam and dodol was and %, respectively.
Berdasarkan percobaan yang kami lakukan dengan mematuhi langkah-langkah percobaan yang telah disebutkan di atas, maka hasil yang kami dapatkan pada larutan pertama dan kedua mempunyai pH 6 (menunjukkan basa); larutan ketiga mempunyai pH 3 (asam); larutan keempat mempunyai pH 13 (basa); larutan kelima mempunyai pH 7 (netral); larutan keenam mempunyai pH 1 (asam); larutan ketujuh mempunyai pH 8 (basa); larutan kedelapan mempunyai pH 6 (asam); putih telur mempunyai pH 10 (basa); kuning telur mempunyai pH 7 (netral); jeruk nipis mempunyai pH 2 (asam); pisang mempunyai pH 5 (asam); dan tomat mempunyai pH 4 (asam).