The Experts below are selected from a list of 84 Experts worldwide ranked by ideXlab platform

Paul P Van Veldhoven - One of the best experts on this subject based on the ideXlab platform.

  • 1 o hexadecyl 2 desoxy 2 amino sn glycerol a substrate for human sphingosine kinase
    2002
    Co-Authors: Sofie Gijsbers, Stanny Asselberghs, Piet Herdewijn, Paul P Van Veldhoven
    Abstract:

    The substrate specificity of human sphingosine kinase was investigated using a bacterially expressed poly(His)-tagged protein. Only the D-Erythro Isomer of the sphingoid bases, sphinganine and sphingenine, was effectively phosphorylated. Long chain 1-alkanols, alkane-1,2-diols, 2-amino-1-alkanol or 1-amino-2-alkanol and short chain 2-amino-1,3-alkanediols were very poor substrates, indicating that the kinase is recognizing the chain length and the position of the amino and secondary hydroxy group. A free hydroxy group at carbon 3 is not a prerequisite, however, since 1-O-hexadecyl-2-desoxy-2-amino-sn-glycerol was an efficient substrate with an apparent K(m) value of 3.8 microM (versus 15.7 microM for sphingenine). This finding opens new perspectives to design sphingosine kinase inhibitors. It also calls for some caution since it cannot be excluded that this ether lipid analogue is formed from precursors that are frequently used in research on platelet activating factor or from phospholipid analogues which are less prone to degradation.

Sofie Gijsbers - One of the best experts on this subject based on the ideXlab platform.

  • 1 o hexadecyl 2 desoxy 2 amino sn glycerol a substrate for human sphingosine kinase
    2002
    Co-Authors: Sofie Gijsbers, Stanny Asselberghs, Piet Herdewijn, Paul P Van Veldhoven
    Abstract:

    The substrate specificity of human sphingosine kinase was investigated using a bacterially expressed poly(His)-tagged protein. Only the D-Erythro Isomer of the sphingoid bases, sphinganine and sphingenine, was effectively phosphorylated. Long chain 1-alkanols, alkane-1,2-diols, 2-amino-1-alkanol or 1-amino-2-alkanol and short chain 2-amino-1,3-alkanediols were very poor substrates, indicating that the kinase is recognizing the chain length and the position of the amino and secondary hydroxy group. A free hydroxy group at carbon 3 is not a prerequisite, however, since 1-O-hexadecyl-2-desoxy-2-amino-sn-glycerol was an efficient substrate with an apparent K(m) value of 3.8 microM (versus 15.7 microM for sphingenine). This finding opens new perspectives to design sphingosine kinase inhibitors. It also calls for some caution since it cannot be excluded that this ether lipid analogue is formed from precursors that are frequently used in research on platelet activating factor or from phospholipid analogues which are less prone to degradation.

Stanny Asselberghs - One of the best experts on this subject based on the ideXlab platform.

  • 1 o hexadecyl 2 desoxy 2 amino sn glycerol a substrate for human sphingosine kinase
    2002
    Co-Authors: Sofie Gijsbers, Stanny Asselberghs, Piet Herdewijn, Paul P Van Veldhoven
    Abstract:

    The substrate specificity of human sphingosine kinase was investigated using a bacterially expressed poly(His)-tagged protein. Only the D-Erythro Isomer of the sphingoid bases, sphinganine and sphingenine, was effectively phosphorylated. Long chain 1-alkanols, alkane-1,2-diols, 2-amino-1-alkanol or 1-amino-2-alkanol and short chain 2-amino-1,3-alkanediols were very poor substrates, indicating that the kinase is recognizing the chain length and the position of the amino and secondary hydroxy group. A free hydroxy group at carbon 3 is not a prerequisite, however, since 1-O-hexadecyl-2-desoxy-2-amino-sn-glycerol was an efficient substrate with an apparent K(m) value of 3.8 microM (versus 15.7 microM for sphingenine). This finding opens new perspectives to design sphingosine kinase inhibitors. It also calls for some caution since it cannot be excluded that this ether lipid analogue is formed from precursors that are frequently used in research on platelet activating factor or from phospholipid analogues which are less prone to degradation.

Piet Herdewijn - One of the best experts on this subject based on the ideXlab platform.

  • 1 o hexadecyl 2 desoxy 2 amino sn glycerol a substrate for human sphingosine kinase
    2002
    Co-Authors: Sofie Gijsbers, Stanny Asselberghs, Piet Herdewijn, Paul P Van Veldhoven
    Abstract:

    The substrate specificity of human sphingosine kinase was investigated using a bacterially expressed poly(His)-tagged protein. Only the D-Erythro Isomer of the sphingoid bases, sphinganine and sphingenine, was effectively phosphorylated. Long chain 1-alkanols, alkane-1,2-diols, 2-amino-1-alkanol or 1-amino-2-alkanol and short chain 2-amino-1,3-alkanediols were very poor substrates, indicating that the kinase is recognizing the chain length and the position of the amino and secondary hydroxy group. A free hydroxy group at carbon 3 is not a prerequisite, however, since 1-O-hexadecyl-2-desoxy-2-amino-sn-glycerol was an efficient substrate with an apparent K(m) value of 3.8 microM (versus 15.7 microM for sphingenine). This finding opens new perspectives to design sphingosine kinase inhibitors. It also calls for some caution since it cannot be excluded that this ether lipid analogue is formed from precursors that are frequently used in research on platelet activating factor or from phospholipid analogues which are less prone to degradation.

Pere Clapes - One of the best experts on this subject based on the ideXlab platform.

  • serine hydroxymethyl transferase from streptococcus thermophilus and l threonine aldolase from escherichia coli as stereocomplementary biocatalysts for the synthesis of β hydroxy α ω diamino acid derivatives
    2008
    Co-Authors: Mariana L Gutierrez, Stefano Servi, Xavier Garrabou, Eleonora Agosta, Teodor Parella, Jesus Joglar, Pere Clapes
    Abstract:

    A novel serine hydroxymethyl transferase from Streptococcus thermophilus (SHMT) and a L-threonine aldolase from Escherichia coli (LTA) were used as stereocomplementary biocatalysts for the aldol addition of glycine to N-Cbz amino aldehydes and benzyloxyacetaldehyde (Cbz=benzyloxycarbonyl). Both threonine aldolases were classified as low-specific L-allo-threonine aldolases, and by manipulating reaction parameters, such as temperature, glycine concentration, and reaction media, SHMT yielded exclusively L-Erythro diastereomers in 34-60 % conversion, whereas LTA gave L-threo diastereomers in 30:70 to 16:84 diastereomeric ratios and with 40-68 % conversion to product. SHMT is among the most stereoselective L-threonine aldolases described. This is due, among other things, to its activity-temperature dependence: at 4 degrees C SHMT has high synthetic activity but negligible retroaldol activity on L-threonine. Thus, the kinetic L-Erythro Isomer was largely favored and the reactions were virtually irreversible, highly stereoselective, and in turn, gave excellent conversion. It was also found that treatment of the prepared N-Cbz-gamma-amino-beta-hydroxy-alpha-amino acid derivatives with potassium hydroxide (1 m) resulted in the spontaneous formation of 2-oxazolidinone derivatives of the beta-hydroxyl and gamma-amino groups in quantitative yield. This reaction might be useful for further chemical manipulations of the products.