Annales Bogorienses

1-8

Authors: Adi Santoso, Arizah Kusumawati

The rhIFN α2a is expressed as a fusion protein containing thioredoxine and polyhistidine sites at its N terminal. Our previous research has obtained recombinant human IFN α2a (rhIFN α2a) protein that expressed predominantly as a soluble form in E. coli BL21(DE3). Through systematic approach of various culture conditions, the aim of current this research is to acquire the best condition and its stability of recombinant rhIFN α2a fusion protein in a culture under study. Expression optimization performed by using three parameters, i.e.: temperature, induction time and inducer concentration. Various IPTG concentrations are 0.25 mM, 0.5 mM, 0.75 mM and 1.0 mM. The incubation time of bacterial cell culture carried out in 3, 4, and 5 hours at temperature 28, 30, and 37°C. The best condition was used to analyze the stability of rhIFN α2a protein expression up to ten generation. The expressed protein was analyzed using SDS PAGE and CBB staining. The optimal culture condition was found to be 37°C temperature with 4 hours time of induction and 1 mM IPTG concentration. Stability analysis revealed that the rhFN α2a protein expression remained stable until the tenth generation with molecular weight, approximately, 36 kDa.

17-28

Authors: Sri Kartika Wijaya, Arizah Kusumawati, Andri Wardiana, Yana Rubiana, Ulfatul Husnaa, Adi Santoso

The urgency to develop a new protein based subunit vaccine candidate against Brucella was provoked by its frequent infection to human and lives stock. Since Brucella melitensis is found as the most species isolated from human, thus the outer membrane of the Brucella melitensis become prominent subcellular location for searching promising antigen to be developed as vaccine target due to its interaction with cell host. Among other proteins suggested by Vaxign program, the OMP31 is found as a promising candidate. Moreover, analysis on other subcellular location leads our interest to SODc protein, which is expected to support the OMP31 in triggering immune response. The OMP31-SODc divalent vaccine candidate was analysed in-silico to predict its stable three-dimensional structure, cloning process and expectation on the ease during expression, purification and the protein vaccine delivery to develop expected immune response.

37-42

Authors: Andri Fadillah Martin, Betalini Widhi Hapsari, Tri Muji Ermayanti

Tacca leontopetaloides (L.) Kuntze which belongs to family Taccaceae is one of tuberous plant useful as an alternative food. This plant contains starch (amylose and amylopectin) similar to that of potato. In addition, this plant also contains secondary metabolites potential for diarrhea, dysentery, and anticancer. In Indonesia, this plant grows at coastal areas i.e. in Sukabumi, Yogyakarta, Garut and Karimunjawa, so this plant was suspected to have high tolerance on salinity stress. The purpose of this research was to investigate the effect of increase in NaCl concentrations on growth and its proline content of T. leontopetaloides grown in vitro. In vitro shoot tips were cultured on MS medium (Murashige & Skoog, 1962) supplemented with NaCl at concentrations of 10; 25; 50; 75; 100; 150 and 200 mM, respectively. After six weeks in culture, shoots height, shoots number, leaves number, fresh weight, as well as their proline content were recorded. The results showed that fresh weight of shoots grown on MS medium supplemented with NaCl from 10 to 100 mM was hogher compared to those of the control treatment. Fresh weight decreased when shoots were cultured on MS medium supplemented with NaCl at more than 100 mM. Height of shoots, number of shoots, and number of leaves decreased along with the increase of NaCl concentrations. The best medium for growth was MS medium supplemented with 25 mM NaCl. In this medium proline content was 15.7 umol/g FW. Proline concentrations increased along with the increase of NaCl concentrations. LD50 value was 146 mM NaCl. In conclusion that on MS medium without addition of plant growth regulators, T. leontopetaloides shoot culture was sensitve to the increase of NaCl concentration.