Purification, characterization, and localization of linamarase in cassava
Material type:![Article](/opac-tmpl/lib/famfamfam/AR.png)
- Manihot esculenta
- CYANOGENESIS
- Leaves
- LINAMARASE
- Hydrolysis
- LINAMARIN
- Roots
- HCN CONTENT
- Analysis
- USA
- COMPOSITION
- CYANOGENIC GLUCOSIDES
- Enzymes
- North America
- Plant anatomy
- Starch crops
- Manihot esculenta
- CIANOGENESIS
- Hojas
- LINAMARASA
- Hidrolisis
- LINAMARINA
- RAICES
- CONTENIDO DE HCN
- ANALISIS
- EE.UU
- Journal articles
- Artículos en revistas
- Cassava
- Yuca
- CIAT MENCION
- Electronic documents
- Documentos electrónicos
- Journal article
- 37180
Item type | Current library | Collection | Call number | Copy number | Status | Date due | Barcode | Item holds | |
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CIAT Library Web | Electronic Document | 37180 (Browse shelf(Opens below)) | Not For Loan (Restricted Access) | |||||
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CIAT Library Document collection CINFOS | Document Collection CINFOS | 37180 (Browse shelf(Opens below)) | c.1 | Short Loan | 100056561 |
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Se purifico linamarasa de yuca a homogeneidad aparente mediante un procedimiento simplificado de extraccion, utilizando tampon de fosfato de pH bajo. Se identificaron 3 isozimas de linamarasa de yuca en hojas, con base en diferencias en punto isoelectrico. La enzima puede hidrolizar varios beta-glicosidos ademas de linamarina; es inusualmente estable y posee una temp. optima de 55 grados C. Estudios de marcacion reactiva inmunologica con coloides de oro indican que la linamarasa se localiza en las paredes celulares del tejido foliar de la yuca. Ya que la linamarina debe atravesar la pared celular despues de la sintesis foliar para transportarse a la raiz, es probable que deba cruzar la pared celular en forma no hidrolizable, posiblemente como el diglucosido linustatina. Ademas, se cuantificaron los niveles de actividad de linamarina y linamarasa en hojas de var. de yuca que difieren en contenido de linamarina en sus raices. No se observaron diferencias sustanciales en el contenido de linamarina en equilibrio dinamico ni en la actividad de linamarasa de hojas de var. con alto o bajo contenido cianogenico radical. Estos resultados indican que los niveles de linamarina y linamarasa en equilibrio dinamico en hojas de var. con alto y bajo contenido cianogenico no se correlacionan con las diferencias var. en los niveles de linamarina en equilibrio dinamico en las raices. (RA-CIAT) spa
We have purified cassava (Manihot esculenta) linamarase to apparent homogeneity using a simplified extraction procedure using low pH phosphate buffer. Three isozymes of cassava linamarase were identified in leaves based on differences in isoelectric point. The enzyme is capable of hydrolyzing a number of beta-glycosides in addition to linamarin. The enzyme is unusually stable and has a temperature optimum of 55 degrees C. Immunogold labeling studies indicate that linamarase is localized in the cell walls of cassava leaf tissue. Since linamarin must cross the cell wall following synthesis in the leaf for transport to the root, it is likely that linamarin must cross the cell wall in a nonhydrolyzable form, possibly as the diglucoside, linustatin. In addition, we have quantified the levels of linamarin and linamarase activity in leaves of cassava varieties which differ in the linamarin content of their roots. We observed no substantial differences in the steady state linamarin content or linamarase activity of leaves from high or low (root) cyanogenic varieties. These results indicate that the steady state levels of linamarin and linamarase in leaves of high and low cyanogenic varieties are not correlated with the varietal differences in the steady state levels of linamarin in roots. (AS) eng