02286nas a2200193   4500008004100000245009100041210006900132300001100201490000700212520140500219653025701624653001201881100001501893700001501908700001901923700002701942700001701969856010601986       2002                        eng d00aCalnexin overexpression increases manganese peroxidase production in Aspergillus niger0 aCalnexin overexpression increases manganese peroxidase productio  a846-510 v683 aHeme-containing peroxidases from white rot basidiomycetes, in contrast to most proteins of fungal origin, are poorly produced in industrial filamentous fungal strains. Factors limiting peroxidase production are believed to operate at the posttranslational level. In particular, insufficient availability of the prosthetic group which is required for peroxidase biosynthesis has been proposed to be an important bottleneck. In this work, we analyzed the role of two components of the secretion pathway, the chaperones calnexin and binding protein (BiP), in the production of a fungal peroxidase. Expression of the Phanerochaete chrysosporium manganese peroxidase (MnP) in Aspergillus niger resulted in an increase in the expression level of the clxA and bipA genes. In a heme-supplemented medium, where MnP was shown to be overproduced to higher levels, induction of clxA and bipA was also higher. Overexpression of these two chaperones in an MnP-producing strain was analyzed for its effect on MnP production. Whereas bipA overexpression seriously reduced MnP production, overexpression of calnexin resulted in a four- to fivefold increase in the extracellular MnP levels. However, when additional heme was provided in the culture medium, calnexin overexpression had no synergistic effect on MnP production. The possible function of these two chaperones in MnP maturation and production is discussed.10aAspergillus niger/*enzymology/genetics Calcium-Binding Proteins/*metabolism Calnexin Culture Media *Fungal Proteins HSP70 Heat-Shock Proteins/metabolism Heme/metabolism Peroxidases/*biosynthesis/genetics Phanerochaete/enzymology/genetics Transformation10aGenetic1 aConesa, A.1 aJeenes, D.1 aArcher, D., B.1 avan den Hondel, C., A.1 aPunt, P., J.  uhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=1182322701436nas a2200157   4500008004100000245005900041210005800100300001100158490000700169520072900176653020800905100001501113700001701128700002701145856010601172       2002                        eng d00aFungal peroxidases: molecular aspects and applications0 aFungal peroxidases molecular aspects and applications  a143-580 v933 aPeroxidases are oxidoreductases that utilize hydrogen peroxide to catalyze oxidative reactions. A large number of peroxidases have been identified in fungal species and are being characterized at the molecular level. In this manuscript we review the current knowledge on the molecular aspects of this type of enzymes. We present an overview of the research efforts undertaken in deciphering the structural basis of the catalytic properties of fungal peroxidases and discuss molecular genetics and protein homology aspects of this enzyme class. Finally, we summarize the potential biotechnological applications of these enzymes and evaluate recent advances on their expression in heterologous systems for production purposes.10aAmino Acid Sequence Binding Sites Biotechnology Catalysis Fungi/*enzymology Molecular Sequence Data Peroxidases/chemistry/*genetics/metabolism Recombinant Proteins Sequence Homology Substrate Specificity1 aConesa, A.1 aPunt, P., J.1 avan den Hondel, C., A.  uhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=1173872101688nas a2200169   4500008004100000245010100041210006900142300001100211490000800222520084700230653026001077100001501337700001601352700002701368700001701395856010601412       2001                        eng d00aC-terminal propeptide of the Caldariomyces fumago chloroperoxidase: an intramolecular chaperone?0 aCterminal propeptide of the Caldariomyces fumago chloroperoxidas  a117-200 v5033 aThe Caldariomyces fumago chloroperoxidase (CPO) is synthesised as a 372-aa precursor which undergoes two proteolytic processing events: removal of a 21-aa N-terminal signal peptide and of a 52-aa C-terminal propeptide. The Aspergillus niger expression system developed for CPO was used to get insight into the function of this C-terminal propeptide. A. niger transformants expressing a CPO protein from which the C-terminal propeptide was deleted failed in producing any extracellular CPO activity, although the CPO polypeptide was synthesised. Expression of the full-length gene in an A. niger strain lacking the KEX2-like protease PclA also resulted in the production of CPO cross-reactive material into the culture medium, but no CPO activity. Based on these results, a function of the C-terminal propeptide in CPO maturation is indicated.10aAmino Acid Sequence Ascomycota/*enzymology/genetics Aspergillus niger/genetics Base Sequence Chloride Peroxidase/biosynthesis/*chemistry/genetics DNA Primers/genetics Enzyme Precursors/biosynthesis/chemistry/genetics Gene Expression Molecular Chaperones/b1 aConesa, A.1 aWeelink, G.1 avan den Hondel, C., A.1 aPunt, P., J.  uhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=1151386601692nas a2200193   4500008004100000245012800041210006900169300001300238490000800251520081300259653019901072100001501271700002101286700002101307700002001328700002701348700001701375856010601392       2001                        eng d00aExpression of the Caldariomyces fumago chloroperoxidase in Aspergillus niger and characterization of the recombinant enzyme0 aExpression of the Caldariomyces fumago chloroperoxidase in Asper  a17635-400 v2763 aThe Caldariomyces fumago chloroperoxidase was successfully expressed in Aspergillus niger. The recombinant enzyme was produced in the culture medium as an active protein and could be purified by a three-step purification procedure. The catalytic behavior of recombinant chloroperoxidase (rCPO) was studied and compared with that of native CPO. The specific chlorination activity (47 units/nmol) of rCPO and its pH optimum (pH 2.75) were very similar to those of native CPO. rCPO catalyzes the oxidation of various substrates in comparable yields and selectivities to native CPO. Indole was oxidized to 2-oxindole with 99% selectivity and thioanisole to the corresponding R-sulfoxide (enantiomeric excess >98%). Incorporation of (18)O from labeled H(2)18O(2) into the oxidized products was 100% in both cases.10aAspergillus niger/enzymology/genetics Catalysis Chloride Peroxidase/biosynthesis/*genetics Fungal Proteins/biosynthesis/*genetics Recombinant Proteins/biosynthesis/genetics Substrate Specificity1 aConesa, A.1 avan De Velde, F.1 avan Rantwijk, F.1 aSheldon, R., A.1 avan den Hondel, C., A.1 aPunt, P., J.  uhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=1127870101536nas a2200169   4500008004100000245007200041210006700113300001100180490000700191520084500198653014001043100001501183700001701198700001801215700002701233856010601260       2001                        eng d00aThe secretion pathway in filamentous fungi: a biotechnological view0 asecretion pathway in filamentous fungi a biotechnological view  a155-710 v333 aThe high capacity of the secretion machinery of filamentous fungi has been widely exploited for the production of homologous and heterologous proteins; however, our knowledge of the fungal secretion pathway is still at an early stage. Most of the knowledge comes from models developed in yeast and higher eukaryotes, which have served as reference for the studies on fungal species. In this review we compile the data accumulated in recent years on the molecular basis of fungal secretion, emphasizing the relevance of these data for the biotechnological use of the fungal cell and indicating how this information has been applied in attempts to create improved production strains. We also present recent emerging approaches that promise to provide answers to fundamental questions on the molecular genetics of the fungal secretory pathway.10aAnimals Biotechnology/*methods Fungal Proteins/*genetics/*metabolism Fungi/*genetics/*metabolism Humans Recombinant Proteins/metabolism1 aConesa, A.1 aPunt, P., J.1 avan Luijk, N.1 avan den Hondel, C., A.  uhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11495573