Characterization of Glycosylation of an Acidic Pectin Methylesterase in Jelly Fig (Ficus awkeotsang) Achenes

• Main Authors: Eric S.L. Hsiao, 蕭世良
• Other Authors: Jason T.C. Tzen
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/12170699706452408200

碩士 === 國立中興大學 === 生物科技學研究所 === 93 === Abstract Pectin methylesterase (PME) is the key enzyme responsible for the gelation of jelly curd in the water extract of jelly fig (Ficus awkeotasang) achenes. The molecular mass of jelly fig PME, a major protein in jelly fig achenes, was about 38 kDa estimated by SDS-PAGE. Its major function is to de-esterify the methoxylated pectin into a pectic acid. Previously, a cDNA sequence encoding the PME of jelly fig has been obtained and overexpressed in E. coli. The overexpressed PME in E. coli was smaller than the native PME about 3 kDa, and lack of enzymatic activity. In a preliminary analysis, the PME of jelly fig was found as a glycoprotein, and the difference in molecular weight between the native and overexpressed PME was due to glycosylation. Furthermore, jelly fig PME is an N-linked glycoprotein.