TAILIEUCHUNG - Báo cáo khoa học: Organelle and translocatable forms of glyoxysomal malate dehydrogenase The effect of the N-terminal presequence

Many organelle enzymes coded for by nuclear genes have N-terminal sequences, which directs them into the organelle (precursor) and are removed upon import (mature). The experiments described below charac-terize the differences between the precursor and mature forms of water-melon glyoxysomal malate dehydrogenase. Using recombinant protein methods, the precursor (p-gMDH) and mature (gMDH) forms were puri-fied to homogeneity using Ni 2+ –NTA affinity chromatography. Gel filtra-tion and dynamic light scattering have shown both gMDH and p-gMDH to be dimers in solution with p-gMDH having a correspondingly higher molecular weight. . | ềFEBS Journal Organelle and translocatable forms of glyoxysomal malate dehydrogenase The effect of the N-terminal presequence Bryan Cox1 Ma May Chit2 Todd Weaver3 Christine Gietl4 Jaclyn Bailey5 Ellis Bell6 and Leonard Banaszak1 1 Department of Biochemistry Molecular Biology and Biophysics University of Minnesota MN USA 2 Western University of Health Sciences Pomona CA USA 3 Department of Chemistry University of Wisconsin La Crosse WI USA 4 Institute of Botany TechnicalUniversity of Munich Germany 5 Gustavus Adolphus College St Peter MN USA 6 Department of Chemistry University of Richmond VA USA Keywords glyoxysome organelle-precursor malate dehydrogenase protein translocation X-ray diffraction Correspondence L. Banaszak 6-155 Jackson HallUniversity of Minnesota 321 Church St. . Minneapolis MN 55455 USA Fax 1 612 6245121 Tel 1 612 6266597 E-mail banas001@ Received 24 June 2004 revised 2 November 2004 accepted 10 November 2004 doi Many organelle enzymes coded for by nuclear genes have N-terminal sequences which directs them into the organelle precursor and are removed upon import mature . The experiments described below characterize the differences between the precursor and mature forms of watermelon glyoxysomal malate dehydrogenase. Using recombinant protein methods the precursor p-gMDH and mature gMDH forms were purified to homogeneity using Ni2 -NTA affinity chromatography. Gel filtration and dynamic light scattering have shown both gMDH and p-gMDH to be dimers in solution with p-gMDH having a correspondingly higher molecular weight. p-gMDH also exhibited a smaller translational diffusion coefficient Dt at temperatures between 4 and 32 C resulting from the extra amino acids on the N-terminal. Differential scanning calorimetry described marked differences in the unfolding properties of the two proteins with p-gMDH showing additional temperature dependent transitions. In addition some differences were found in the steady .

• Báo cáo khoa học
• Report medicine
• traditional medicine
• scientific reports
• breast cancer
• medicine
• chemical reaction
• medical knowledge
• medical research
• analysis of cytoplasmic
• oxidation
• Crystal structure
• bacteria
• hemoglobin
• cell proliferation
• gastric cancer
• hormone medicine
• tumor cells
• biochemical studies
• environmental medicine