Heterologous expression of cellobiohydrolase II (Cel6A) in maize endosperm.
The technology of converting lignocellulose to biofuels has advanced swiftly over the past few years, and enzymes are a significant constituent of this technology. In this regard, cost effective production of cellulases has been the focus of research for many years. One approach to reach cost targets of these enzymes involves the use of plants as bio-factories. The application of this technology to plant biomass conversion for biofuels and biobased products has the potential for significantly lowering the cost of these products due to lower enzyme production costs. Cel6A, one of the two cellobiohydrolases (CBH II) produced by Hypocrea jecorina, is an exoglucanase that cleaves primarily cellobiose units from the non-reducing end of cellulose microfibrils. In this work we describe the expression of Cel6A in maize endosperm as part of the process to lower the cost of this dominant enzyme for the bioconversion process. The enzyme is active on microcrystalline cellulose as exponential microbial growth was observed in the mixture of cellulose, cellulases, yeast and Cel6A, Cel7A (endoglucanase), and Cel5A (cellobiohydrolase I) expressed in maize seeds. We quantify the amount accumulated and the activity of the enzyme. Cel6A expressed in maize endosperm was purified to homogeneity and verified using peptide mass finger printing.
Arkansas Biosciences Institute, Arkansas State University, PO Box 639, State University, AR 72467, USA.
Shivakumar Pattada
SP
Devaiah
Deborah Vicuna
DV
Requesens
Yeun-Kyung
YK
Chang
Kendall R
KR
Hood
Ashley
A
Flory
John A
JA
Howard
Elizabeth E
EE
Hood
D002482:Cellulose / Q000378:metabolism; D043366:Cellulose 1,4-beta-Cellobiosidase / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D056625:Endosperm / Q000201:enzymology / Q000235:genetics*; D035901:Hypocrea / Q000201:enzymology* / Q000235:genetics; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000254:growth & development; D003313:Zea mays / Q000235:genetics* / Q000254:growth & development
D011994:Recombinant Proteins; D002482:Cellulose; D043366:Cellulose 1,4-beta-Cellobiosidase; C109691:microcrystalline cellulose