Enzyme Distribution Derived from Macroscopic Particle Behavior of an Industrial Immobilized Penicillin-G Acylase

The macroscopic kinetic behavior of an industrially employed immobilized penicillin‐G acylase, called Assemblase, formed the basis for a discussion on some simple intraparticle biocatalytic model distributions. Assemblase catalyzes the synthesis of the widely used semisynthetic antibiotic cephalexin...

Full description

Saved in:

Bibliographic Details
Published in:	Biotechnology progress Vol. 19; no. 5; pp. 1510 - 1518
Main Authors:	Van Roon, Jeroen L., Joerink, Michiel, Rijkers, Marinus P. W. M., Tramper, Johannes, P. H. Schroën, Catharina G., Beeftink, Hendrik H.
Format:	Journal Article
Language:	English
Published:	USA American Chemical Society 01-09-2003 American Institute of Chemical Engineers
Subjects:	active-site titration biocatalyst Biological and medical sciences Biotechnology Catalysis cephalexin Cephalexin - chemical synthesis Chemical Industry - methods diffusion limitation Enzyme Activation Enzyme Stability Enzymes, Immobilized - chemistry Enzymes, Immobilized - ultrastructure Fundamental and applied biological sciences. Psychology Glycine - analogs & derivatives Glycine - chemistry Hydrolysis parameters Particle Size Penicillin Amidase - chemistry Penicillin Amidase - ultrastructure porous solid supports rate-constant Structure-Activity Relationship substrate Immobilization Penicillin amidase Hydrolases Enzyme
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	The macroscopic kinetic behavior of an industrially employed immobilized penicillin‐G acylase, called Assemblase, formed the basis for a discussion on some simple intraparticle biocatalytic model distributions. Assemblase catalyzes the synthesis of the widely used semisynthetic antibiotic cephalexin. Despite the obvious advantages of immobilization, less cephalexin and more of the unwanted byproduct d‐(–)‐phenylglycine are obtained due to diffusional limitations when the immobilized enzyme is employed. To rationally optimize Assemblase, the parameters particle size, enzyme loading, and enzyme distribution, which severely determine the macroscopic particle performance, were studied on the basis of macroscopic observations. Laser diffraction measurements showed that the particle sizes in Assemblase vary as much as 100‐fold. The relative and total enzyme loadings in Assemblase and fractions thereof of different sizes were determined by initial‐rate d‐(–)‐phenylglycine amide hydrolysis, cephalexin synthesis experiments, and active‐site titration. These experiments revealed that the loading of penicillin‐G acylase in Assemblase was inversely correlated with the particle diameter. Apart from enzyme loadings, estimates on the intraparticle enzyme distribution came from cephalexin synthesis experiments, where mass‐transport limitations were present. Although this method cannot provide the level of detail of specific labeling experiments, it is simple, fast, and cheap. Within the set of simple model predictions, a heterogeneous enzyme distribution with most biocatalyst present in the outer region of the particle (within the outer 100 μm) gave the best description of the observed behavior, although no exact correlation was established. Highly detailed determination of intraparticle enzyme distributions must come from immunolabeling.
Bibliography:	ArticleID:BTPR340638 istex:8C5733166508786DCDFDE4AC0CACBB2A81ABD61C ark:/67375/WNG-M4Q416LQ-6 ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2
ISSN:	8756-7938 1520-6033
DOI:	10.1021/bp0340638