Regulation studies of phaC(C1 and C2) genes in Pseudomonas sp. USM 4-55

Among the various biodegradable plastics available, polyhydroxyalkanoates (PHAs) attract a lot of attention because these polymers are produced by bacteria and have thermoplastic properties. They are biodegradable, biocompatible, moisture resistant, versatile, have long shelf life and are made from renewable source materials (Pouton et al., 1996)

ANTIPROLIFERATIVE EFFECT ON BREAST CANCER (MCF7) OF Moringa oleifera SEED EXTRACTS

Background: Moringa oleifera belongs to plant family, Moringaceae and popularly called ―wonderful tree‖, for it is used traditionally to cure many diseases including cancer in Africa and Asia, however, there is limited knowledge on cytotoxic activity of Moringa oleifera seeds on MCF7 breast cancer cell. The present study evaluated antiproliferative effect on MCF7 of the seed. Materials and Methods: Seeds of Moringa oleifera were grinded to powder and its phytochemicals were extracted using water and 80% ethanol solvents, part of the ethanolic extract were sequentially partitioned to fractions with four solvents (hexane, dichloromethane, chloroform, and n-butanol). Antiproliferative effects on MCF7 of the samples were determined. Finally, potent samples that significantly inhibited MCF7 growth were tested on MCF 10A. Results: Crude water extract, hexane and dichloromethane fractions of the seeds inhibited the proliferation of MCF7 with the following IC50 values 280 μg/ml, 130 μg/ml and 26 μg/ml respectively, however, of the 3 samples, only hexane fraction had minimal cytotoxic effect on MCF 10A (IC50 > 400μg/ml). Conclusion: Moringa oleifera seed has antiproliferative effect on MCF7

Cloning and characterization of polyhydroxyalkanoate (PHA) genes from Pseudomonas sp. isolated from Antarctica

Pseudomonas strains accumulate mediumchain-length poly(R)-3-hydroxyalkanoate (PHA) as carbon and energy source under conditions of limiting nutrients in the presence of an excess of carbon source (Fidler et al., 1992)

Biosynthetic production of human growth hormone gene in methylotrophic yeast, Pichia pastoris

Human growth hormone (hGH) is secreted from the anterior pituitary gland and exerts a wide variety of functions such as, IGF-1 production, protein synthesis, glucose metabolism, lipolysis, lipogenesis, and cell proliferation/differentiation (Isaksson et al., 1985; Press, 1988; Thorner and Vance, 1988; Strobl and Thomas, 1994)

An approach towards the prediction of protein tertiary structures: molecular modeling perspectives

Impressive advances in genomic sequencing technologies are flooding us with the complete genetic blueprints of human, rat, mouse, chimpanzee and various microorganisms at an extremely rapid pace. As these DNA sequences continue to accumulate, the challenge to determine the function of each gene is paramount. These functions are determined by their unique three-dimensional (3D) structures as a result of protein folding. Protein folding can be defined as the process in which proteins spontaneously arrange their linear sequence of amino acids into native 3D structures that will allow them to function properly. Thus, elucidation of the 3D structure of a protein is vital in understanding its function. However, it is not known how the newly synthesized polypeptide chains fold into a protein with specific function. It was not until 1973 that Anfinsen [1] postulated that all the information needed for a protein to correctly fold into its native structure is encoded solely in its amino acid sequence and that the native state of the protein is the conformation with the lowest energy. Consequently, this important principle has brought immense interests among the scientists to investigate how proteins fold into their native structures and eventually determine the correct functional fold for the proteins. The two most mature and conventional experimental techniques to solve the structure of a protein are the X-ray crystallography and Nuclear Magnetic Resonance (NMR). John Kendrew and Max Perutz shared the Nobel Prize in 1962 for their pioneering achievement in solving the atomic level structure of the protein myoglobin and hemoglobin, respectively, using X-ray diffraction. Since then, many protein structures were solved and various roles of proteins in living cells were known. Despite the accuracy and the advances of these experimental techniques, such methods are very costly and it may take months to years for solving one structure. The current number of 3D protein structures is very small compared to the number of protein sequences, creating a huge gap between them. It has become more pressing with the growth of genome sequencing projects providing protein sequences for which structural information is not available. As this gap is expected to keep on growing with the ongoing genome projects, the experimental techniques certainly cannot be expected to keep pace with the rapid flow of the sequences. This has caused an urgent need to accurately predict the 3D structure of proteins from the linear chain of amino acid sequence using other methods especially computational work that relies heavily on theoretical studies. However, despite decades of active research and the impressive advances [2,3,4,5], computational protein structure prediction and protein folding remain one of the most important unsolved problems in structural biology today [6,7,8]

Phylogeny and Characterization of Three nifH-Homologous Genes from Paenibacillus azotofixans

In this paper, we report the cloning and characterization of three Paenibacillus azotofixans DNA regions containing genes involved in nitrogen fixation. Sequencing analysis revealed the presence of nifB1H1D1K1 gene organization in the 4,607-bp SacI DNA fragment. This is the first report of linkage of a nifB open reading frame upstream of the structural nif genes. The second (nifB2H2) and third (nifH3) nif homologues are confined within the 6,350-bp HindIII and 2,840-bp EcoRI DNA fragments, respectively. Phylogenetic analysis demonstrated that NifH1 and NifH2 form a monophyletic group among cyanobacterial NifH proteins. NifH3, on the other hand, clusters among NifH proteins of the highly divergent methanogenic archaea

ANTIPROLIFERATIVE EFFECT ON BREAST CANCER (MCF7) OF Moringa oleifera SEED EXTRACTS

Background: Moringa oleifera belongs to plant family, Moringaceae and popularly called ―wonderful tree‖, for it is used traditionally to cure many diseases including cancer in Africa and Asia, however, there is limited knowledge on cytotoxic activity of Moringa oleifera seeds on MCF7 breast cancer cell. The present study evaluated antiproliferative effect on MCF7 of the seed. Materials and Methods: Seeds of Moringa oleifera were grinded to powder and its phytochemicals were extracted using water and 80% ethanol solvents, part of the ethanolic extract were sequentially partitioned to fractions with four solvents (hexane, dichloromethane, chloroform, and n-butanol). Antiproliferative effects on MCF7 of the samples were determined. Finally, potent samples that significantly inhibited MCF7 growth were tested on MCF 10A. Results: Crude water extract, hexane and dichloromethane fractions of the seeds inhibited the proliferation of MCF7 with the following IC50 values 280 μg/ml, 130 μg/ml and 26 μg/ml respectively, however, of the 3 samples, only hexane fraction had minimal cytotoxic effect on MCF 10A (IC50 > 400μg/ml). Conclusion: Moringa oleifera seed has antiproliferative effect on MCF7

Characterization of polyhydroxyalkanoate production capacity, composition and weight synthesized by Burkholderia cepacia JC-1 from various carbon sources

Polyhydroxyalkanoates (PHA) are microbial polymers that have received widespread attention in recent decades as potential alternatives to some petrochemical-based plastics. However, widespread use of PHA is often impeded by its cost of production. Therefore, the search for and systematic investigation of versatile microbial PHA producers capable of using various carbon sources, even in the form of animal fats, for PHA biosynthesis is desirable. This study highlights the PHA production capacity, monomer composition and molecular weight synthesized by Burkholderia cepacia JC-1, a locally isolated strain from soil, from various carbon sources. In the category of simple sugars and plant oils, the use of glucose and palm oil at C:N ratio of 40 resulted in the highest accumulation of 52 wt% and 36 wt% poly(3-hydroxybutyrate) [P(3HB)] homopolymer and dry cell weight of 2.56 g/L and 3.17 g/L, respectively. Interestingly, B. cepacia JC-1 was able to directly utilize animal-derived lipid in the form of crude and extracted chicken fat, resulting in appreciable dry cell weight and PHA contents of up to 3.19 g/L and 47 wt% respectively, surpassing even that of palm oil in the group of triglycerides as substrates. The presence of antibiotics (streptomycin) in cultivation medium did not significantly affect cell growth and polymer production. The supply of sodium pentanoate as a co-substrate resulted in the incorporation of 3-hydroxyvalerate (3HV) monomer at fractions up to 37 mol%. The molecular weight of polymers produced from glucose, palm oil and chicken fat were in the range of 991–2118 kDa, higher than some reported studies involving native strains. The results from this study form an important basis for possible improvements in using B. cepacia JC-1 and crude chicken fats in solid form for PHA production in the future