胃幽門螺旋桿菌是一種常在人類胃部被發現的微需氧的革蘭氏陰性。全球有超過一半以上的人口都有感染胃幽門螺旋桿菌，研究指出胃幽門螺旋桿菌會增加胃潰瘍以及胃癌發生的風險。目前第一線的治療是使用抗生素加質子通道抑制劑的三合一療法治療一周，但發現有越來越多人利用此治療方法無法達到療效原因為幽門螺旋桿菌開始出現抗藥性。所以，找到新的抗菌藥物來治療胃幽門螺旋桿菌是很重要的。
輔酶A生合成途徑是一個好的設計抗菌藥物的研究目標，因為其產物輔酶A是所有生物體生存所必須的輔因子。磷酸泛酸醯基乙胺腺苷轉移酶則是輔酶A生合成途徑中的速率限制步驟。瞭解磷酸泛酸醯基乙胺腺苷轉移酶的反應機制對於針對此蛋白的藥物設計是重要的。近來，胃幽門螺旋桿菌的磷酸泛酸醯基乙胺腺苷轉移酶與輔酶A的結構已經由我們實驗室所解出。將定點突變的磷酸泛酸醯基乙胺腺苷轉移酶以活性分析的方式來找出參與催化的重要胺基酸，以期能提供藥物設計時一些重要的資訊及想法。

H. pylori is a gram-negative and microaerophilic bacterium found in human stomach. It infects more than 50% of the world population and increases the risk of developing gastric ulcer and stomach cancer. The standard first-line is a one week “triple therapy” but an increasing number of infected individuals are found to harbor antibiotic-resistant bacteria. It is important to find a new treatment or antibacterial drug targets to H. pylori.
Coenzyme A (CoA) biosynthesis pathway is a good antimicrobial drug target to inhibit H. pylori infection because Coenzyme A is an essential cofactor in synthesis of oxidation of fatty acid for all living organisms. Phosphopantetheine adenylyltransferase (PPAT) is the rate-limiting enzyme involved in this pathway. Understanding the PPAT catalytic mechanism is important for drugs design. The structure of H. pylori PPAT has been determined recently. I had used the site-directed mutagenesis to identify the critical residues take part in enzyme catalysis by kinetic analysis. It provided important information about those critical residues when designing drugs.

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