[17] Screening techniques for lipase catalyst selection

Ader, U.; Andersch, P.; Berger, Matthias; Goergens, U.; Haase, B.; Hermann, Jacques; Laumen, Kurt; Seemayer, R.; Waldinger, C.; Schneider, Manfred

doi:10.1016/s0076-6879(97)86019-3

Cited by 18 publications

(18 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Consequently, we would predict the accumulating MAG, DAG, and TAG pools to have a similar FA profile in reactions employing glycerol and FA using PS-30 and RM lipases. This would appear to simplify the design process in assembling a structured TAG from basic building blocks in that it can be based on the characteristic FA selectivity of a lipase in reactions with free glycerol as alcohol cosubstrate, for which there are ample data reported in the literature (5)(6)(7)11,16). We have shown this relationship to apply to two specific and widely used lipases, and further validation among other common lipases remains to be seen.…”

Section: Resultsmentioning

confidence: 82%

“…Therefore, quantifying enzyme selectivity in terms of kinetic constants allows one to predict enzyme behavior under conditions where different substrate profiles and concentrations may be considered or anticipated. Selectivity of several lipases toward a host of FA substrates has been quantified in terms of relative selectivity constants (often expressed in ratio format as relative α-values) by several research groups (3)(4)(5)(6)(7)(8)(9)(10)(11). In all cases, free alcohols or acetate esters of alcohol were employed as cosubstrates.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Reaction selectivity of rhizomucor miehei lipase as influenced by monoacylation of sn‐glycerol

Parkin

2004

J Americ Oil Chem Soc

View full text Add to dashboard Cite

Reaction selectivities were determined in multicompetitive reactions mediated by Rhizomucor miehei (RM) lipase at water activity of 0.19 in hexane. Saturated FA (C4-C18 even chain) and oleic acid (C18:1) were reacted with a single alcohol, glycerol, or α-or β-MAG containing C4, C10, C16, or C18:1 individually as alcohol cosubstrate. Similar patterns of broad FA selectivity toward C8-C18 FA were generally observed for esterification into specific acylglycerol (AG) pools with the different α/β-CX-MAG cosubstrates. Exceptions were enrichment of C18 in the MAG pool with α-C16-MAG substrate, and a general suppression of C4/C6 FA reactivity and a specific discrimination toward >C8 FA incorporation into the TAG pool, both for reactions with α-C10-and α-C16-MAG. RM lipase selectivity toward MAG was in descending order: β-Selectivity in channeling CX of the original CX-MAG substrates into higher AG species was in descending order:Aside from their characteristic FA selectivity, Burkholderia cepacia (PS-30) and RM lipases behaved similarly in terms of MAG selectivity as well as a general conservation of FA selectivity throughout the sequential steps of TAG assembly from FA and glycerol for processes designed to yield specifically structured TAG.The prospect of using lipases to prepare uniquely functional "structured glycerides" for food and allied industries represents an opportunity to add value to basal lipid resources (1). The scientific literature is rife with examples of empirical or archival accounts of how lipids may be transformed by lipases into derivatives of enhanced functionality for specific applications. However, to fully exploit the synthetic power of lipases for these purposes, a comprehensive understanding of substrate and product selectivity patterns is required. This would enable the development of cogent strategies to use specific lipases to convert various lipid mixtures into desired structured glyceride derivatives.One can envision the de novo assembly of structured TAG as a three-step, incremental process of selective acylation of each of the three sn-glycerol hydroxyl groups. Selectivity of enzymic reactions is quantitatively indexed in terms of specificity constants (k cat /K M , which is directly proportional to V max /K M ), and such constants are applicable at any substrate concentration (2). Therefore, quantifying enzyme selectivity in terms of kinetic constants allows one to predict enzyme behavior under conditions where different substrate profiles and concentrations may be considered or anticipated. Selectivity of several lipases toward a host of FA substrates has been quantified in terms of relative selectivity constants (often expressed in ratio format as relative α-values) by several research groups (3)(4)(5)(6)(7)(8)(9)(10)(11). In all cases, free alcohols or acetate esters of alcohol were employed as cosubstrates. What is not known is how progressive acylation of the snglycerol backbone, yielding different alcohol cosubstrates, may modulate lipase selectivity toward FA for subsequent est...

show abstract

Section: Resultsmentioning

confidence: 82%

mentioning

confidence: 99%

Reaction selectivity of rhizomucor miehei lipase as influenced by monoacylation of sn‐glycerol

Parkin

2004

J Americ Oil Chem Soc

View full text Add to dashboard Cite

show abstract

“…The competitive factor (also commonly referred to as relative selectivity constant or α-value) among multiple FA substrates was determined based on the kinetic model advanced previously (6,18) as applied in previous studies (8)(9)(10). α-Values were analyzed experimentally as progress of reactivity of one (or more) substrate(s) relative to a reference substrate (C8 FA in this study), according to the following equation: [1] where subscripts A and B represent competing substrates and the reference substrate, respectively.…”

Section: Methodsmentioning

confidence: 99%

“…Selectivity constants may be used to predict the pattern of lipase reactivity under a broad range of conditions where substrate identity and levels are variable, since kinetic constants are not concentration-dependent. Many groups have used this approach to quantify the discriminatory power of various lipases among substrates for esterification reactions between FA and alcohols (6)(7)(8)(9)(10).…”

mentioning

confidence: 99%

Reaction selectivity of Burkholderia cepacia (PS‐30) lipase as influenced by monoacylation of sn‐glycerol

Parkin

2004

J Americ Oil Chem Soc

View full text Add to dashboard Cite

Reaction selectivities were determined in multicompetitive reactions mediated by Burkholderia cepacia lipase (Amano PS-30) at a water activity of 0.19 in hexane. Saturated FA (C4-C18 even chain) and oleic acid (C18:1) were reacted with a single alcohol, glycerol, or α-or β-MAG, containing C4, C10, C16, or C18:1 individually as alcohol cosubstrate. Similar ordinal patterns of FA selectivity, with C8, C10, and C16 preferred over others, were generally observed for incorporation of FA into specific acylglycerol (AG) pools of the 24 specific cases evaluated. The three exceptions were enrichment of C14 and C18 in the MAG pool with α-C16-MAG substrate, and a general suppression of >C8 incorporation into the TAG pool for reactions with α-C10-and α-C16-MAG. PS-30 lipase selectivity toward MAG was in descending order: α/β-C4-MAG > β-C10-MAG > β-C16-MAG > α/β-C18:1-MAG > α-C10-MAG > α-C16-MAG. Selectivity in channeling CX of the original CX-MAG substrates into higher AG species was in descending order: α-Generally, MAG were better acyl donors than FA for esterification reactions leading to DAG formation. These observations are relevant to the design of biocatalytic processes intended to yield specifically structured TAG.A focus of over a decade of recent research on exploiting the synthetic power of lipases in organic media is the prospect of preparing value-added or functional "structured glycerides" for food and pharmaceutical industries (1). Examples of lipids modified by lipase to confer additional value and/or functionality include low-calorie fats (2), cocoa butter substitutes (3), and nutritional lipids (4,5). The applications-driven research in this area has focused largely on using specific lipid mixtures or even pure reaction components to prepare specific targets of synthesis. Much of this body of literature has been rather empirical and sparingly reliant on features of lipase selectivity, such as regioselectivity. Indeed, the commercial and economic justifications for using a lipase over any chemical modification process are embedded in the multifaceted patterns of selectivity offered by an enzymatic reaction.To facilitate the broadest possible application of lipases to modify lipids for added value, it is imperative to develop an understanding of lipase selectivity patterns in a manner that allows the application of such knowledge to a host of possible reactions, where the identity and levels of lipid substrates may be quite varied. One approach that fulfills this need is the determination of relative kinetic constants that define the substrate selectivity patterns of various lipases. Selectivity constants may be used to predict the pattern of lipase reactivity under a broad range of conditions where substrate identity and levels are variable, since kinetic constants are not concentration-dependent. Many groups have used this approach to quantify the discriminatory power of various lipases among substrates for esterification reactions between FA and alcohols (6-10).Our approach has focused on kinetically chara...

show abstract

“…Selectivity of several lipases toward a host of fatty acid (FA) substrates and simple alcohols, including glycerol, has been quantified in terms of relative selectivity constants (expressed as relative a-values) (Ader et al, 1997;Chang, Lee, & Parkin, 1999;Kirk, Bj€ orkling, Godtfredsen, & Larsen, 1992;Lee & Parkin, 2000;Rangheard, Langrand, Triantaphylides, & Baratti, 1989;Rangheard, Langrand, Triantaphylides, & Baratti, 1992). While these studies with glycerol were instrumental in describing FA selectivity of the lipases studies, they did not address whether lipase selectivity for FA becomes modified as the sn-glycerol backbone becomes progressively acylated, leading to the accumulation of TAG.…”

Section: Introductionmentioning

confidence: 99%

Selectivity of fatty acid incorporation into acylglycerols in esterification reactions using Rhizomucor miehei and Burkholderia cepacia lipases

Parkin

2004

Food Research International

View full text Add to dashboard Cite

[17] Screening techniques for lipase catalyst selection

Cited by 18 publications

References 26 publications

Reaction selectivity of rhizomucor miehei lipase as influenced by monoacylation of sn‐glycerol

Reaction selectivity of rhizomucor miehei lipase as influenced by monoacylation of sn‐glycerol

Reaction selectivity of Burkholderia cepacia (PS‐30) lipase as influenced by monoacylation of sn‐glycerol

Selectivity of fatty acid incorporation into acylglycerols in esterification reactions using Rhizomucor miehei and Burkholderia cepacia lipases

Contact Info

Product

Resources

About