PSU Knowledge Bank Collection:http://kb.psu.ac.th:80/psukb/handle/2553/12502024-03-29T02:06:00Z2024-03-29T02:06:00ZExpression of Genes Involving Disease Resistance in Citrus Fruit Induced by Bacillus subtillis Lipopeptides Elicitors and Fungal PathogenPaiboon Tunsagoolhttp://kb.psu.ac.th:80/psukb/handle/2016/190312023-11-13T06:38:25Z2018-01-01T00:00:00ZTitle: Expression of Genes Involving Disease Resistance in Citrus Fruit Induced by Bacillus subtillis Lipopeptides Elicitors and Fungal Pathogen
Authors: Paiboon Tunsagool
Abstract: Cyclic lipopeptides (CLPS) obtained from Bacillus subtilis ABS-S14 had ability to activate some important genes, proteins, and metabolites which are involved in plant defensive pathways to stress responses and infection caused by Penicillium digitatum in mandarin fruit. The effects of CLP extract, fengycin, iturin A and surfactin in enhancement of the expression of PAL, LOX, ACS1, ACO, CHI, GLU, POD and PR1 genes in postharvest mandarin fruit were revealed. Also the proteins relating to Ca2+ pathway, ABA signaling pathway, reactive oxygen species pathway, and ubiquitin- proteasome system including energy production for plant resistance were significantly accumulated. During stress responses (non-fungal infection), fengycin activated plant production of a protein that is involved in plant development and the ubiquinone biosynthetic process while iturin A and surfactin were shown to be involved in auxin and abscisic acid modulating signaling pathways. In addition, a comparative elicitor-protein binding assay of each CLP illustrated that iturin A attached to 12-oxophytodienoate reductase 2 that plays role in oxylipin biosynthetic process required for jasmonic acid production led to inducing systemic resistance (ISR). Furthermore, metabolomic analysis revealed that CLPs elicited a high accumulation of some amino acids; aspartic acid, homoserine, threonine, serine, glycine and tryptophan, which are primary metabolites via the metabolism of glycine, serine and threonine, and the secondary metabolites; serotonin and tyramine, which are active in the metabolism of tryptophan and tyrosine, respectively in postharvest mandarin fruit.
Description: Thesis (Ph.D., Biochemistry)--Prince of Songkla University, 20182018-01-01T00:00:00Zการศึกษาโปรตีนสารพิษ Alpha-Hemolysin (HlyA) ของเชื้อ Escherichia coli สายพันธุ์ที่ก่อให้เกิดโรคติดเชื้อในระบบทางเดินปัสสาวะกนกพร ปานทองhttp://kb.psu.ac.th:80/psukb/handle/2016/180622023-04-21T04:14:14Z2022-01-01T00:00:00ZTitle: การศึกษาโปรตีนสารพิษ Alpha-Hemolysin (HlyA) ของเชื้อ Escherichia coli สายพันธุ์ที่ก่อให้เกิดโรคติดเชื้อในระบบทางเดินปัสสาวะ
Authors: กนกพร ปานทอง
Abstract: Uropathogenic Escherichia coli (UPEC) is the main cause of urinary tract infection (UTI) worldwide. The exotoxin hemolysin A (HlyA) is a virulence factor that plays important role in the mechanism of UTI and indicates the severity of UTI symptoms. HlyA induces the pore formation in membrane of the host cells. It functions as the active HlyA which is activated by HlyC in the acylation reaction. The main objective of this research is to express and purify both HlyA and HlyC proteins as well as to preliminary study the biochemical properties. Constructing the recombinant plasmids pET17b-hlyA encoding HlyA and pET17b-hlyC encoding HlyC by using UPEC genomics isolated from UTI patients admitted to the hospital in southern Thailand as a template revealed that nucleotide sequences of hlyA and hlyC genes were different from other UPEC strains i.e. CFT073, J96 and UTI89, with the most similarity to CFT073 corresponding to 99.2% and 98.8%, respectively. The UPEC strain of this research was therefore designated as strain MNT08. Both HlyA and HlyC proteins were overexpressed as insoluble proteins at 37 °C and 25 °C respectively in E. coli strain BL21(DE3). After a single-step purification using Ni-NTA affinity chromatography , the purified HlyA and HlyC proteins were analysed by SDS-PAGE revealing a molar mass of approximately 110 kDa and 19 kDa, respectively. Based on mass spectrometry, the purified HlyA protein was identified as hemolysin with 55% similarity to hemolysin encoded by hlyA gene from UPEC (Accession number: P09983) while HlyC had 56% similarity to hemolysin-activating lysine-acyltransferase HlyC from UPEC (Accession number: P09984). HlyA is expressed as an unfolded protein called pro-HlyA. Normally, pro-HlyA can folding in the condition with Ca2+, which is interaction on the RTX domain. HlyA was successfully folded in a buffer containing 50 mM Tris-HCl pH 7.4, 50 mM NaCl, and 20 mM CaCl2. A preliminary study on the structural and functional relationships of proteins. The three-dimensional structural of the HlyA protein was created using SWISS-MODEL. A homology model of HlyA protein was generated using the structure of CyaA from Bordetella pertussis, which has a T1SS secretion system like HlyA from E. coli, as the most suitable template. The model was predicted as a monomer covering 339 amino acids at the C-terminus (residues 612-950). Due to the limitation of short-length template, the model in this research was able to predict only one-third portion of HlyA structure. Meanwhile, ApxC of Actinobacillus pleuropneumoniae was used as a template for homology modeling of HlyC. The HlyC model was built as a homodimer covering 167 amino acids (residues 3-169), accounting for 98.2% of the total amino acid residues. To sum up, this research is only a preliminary study providing useful information for further functional and structural studies of the full length HlyA using X-ray crystallography in order to acquire a better understanding of the pore formation in UTI mechanism.
Description: วิทยาศาสตรมหาบัณฑิต (ชีวเคมี), 25652022-01-01T00:00:00ZTransthyretin Amyloidosis Therapy: A possibility in "Brahmi" (Centella asiatica and Bacopa monnieri) phytochemicalsEze Fredrick Nwudehttp://kb.psu.ac.th:80/psukb/handle/2016/171662021-07-24T06:36:40Z2019-01-01T00:00:00ZTitle: Transthyretin Amyloidosis Therapy: A possibility in "Brahmi" (Centella asiatica and Bacopa monnieri) phytochemicals
Authors: Eze Fredrick Nwude
Description: Thesis (Ph.D., Biochemistry)--Prince of Songkla University, 20192019-01-01T00:00:00ZStudy on anti-atherosclerotic mechanisms of Morelloflavone from Garcinia dulcis LeavesDecha Pinkaewhttp://kb.psu.ac.th:80/psukb/handle/2016/135242021-04-27T02:57:32Z2008-01-01T00:00:00ZTitle: Study on anti-atherosclerotic mechanisms of Morelloflavone from Garcinia dulcis Leaves
Authors: Decha Pinkaew
Description: Thesis (Ph.D., Biochemistry)--Prince of Songkla University, 20082008-01-01T00:00:00Z