Publications by authors named "Janocha S"

CYP106A2 from Bacillus megaterium ATCC13368, was identified in the 1970s as one of the first bacterial steroid hydroxylases responsible for the conversion of progesterone to 15β-hydroxyprogesterone. Later on it has been proven to be a potent hydroxylase of numerous 3-oxo-Δ as well as 3-hydroxy-Δ-steroids and has recently also been characterized as a regioselective allylic bacterial diterpene hydroxylase. The main hydroxylation position of CYP106A2 is thought to be influenced by the functional groups at C3 position in the steroid core leading to a favored 15β-hydroxylation of 3-oxo-Δ-steroids and 7β-hydroxylation of 3-hydroxy-Δ-steroids.

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CYP106A2 from Bacillus megaterium ATCC 13368 is known as a bacterial steroid hydroxylase that is also capable of hydroxylating a variety of terpenoids. To analyze the substrate specificity of this enzyme further, different resin acids of the abietane and pimarane types were tested with regard to binding and conversion. Product formation could be shown for all tested substrates.

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Terpenoids comprise a highly diverse group of natural products. In addition to their basic carbon skeleton, they differ from one another in their functional groups. Functional groups attached to the carbon skeleton are the basis of the terpenoids' diverse properties.

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Since the first description of apoptosis four decades ago, great efforts have been made to elucidate, both in vivo and in vitro, the molecular mechanisms involved in its regulation. Although the role of cytochrome c during apoptosis is well established, relatively little is known about its participation in signaling pathways in vivo due to its essential role during respiration. To obtain a better understanding of the role of cytochrome c in the onset of apoptosis, we used a proteomic approach based on affinity chromatography with cytochrome c as bait in this study.

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Programmed cell death is an event displayed by many different organisms along the evolutionary scale. In plants, programmed cell death is necessary for development and the hypersensitive response to stress or pathogenic infection. A common feature in programmed cell death across organisms is the translocation of cytochrome c from mitochondria to the cytosol.

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Cytochrome P450 enzymes exhibit a tremendous potential for biotechnological applications due to their ability to introduce oxygen into non-activated carbon atoms. Their catalytic diversity is complemented by a broad substrate range covering many natural compounds. Especially the functionalization of terpenoids by P450s becomes increasingly interesting due to the diverse biological effects of these compounds.

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The members of the CYP109 family (CYP109C1, CYP109C2, and CYP109D1) from Sorangium cellulosum So ce56 are among the 21 P450 enzymes, of which only CYP109D1 and CYP264B1 have so far been functionally characterized. Here, we attempted to characterize two other P450s (CYP109C1 and CYP109C2) for the first time and compare their biochemical, biophysical, and functional properties to those of the fatty acid hydroxylating CYP109D1. Considering the physiological importance of fatty acids, we investigated saturated fatty acid binding and conversion for all members of the CYP109 family.

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Cytochrome P450s are very versatile enzymes with great potential for biotechnological applications because of their ability to oxidize unactivated CH bonds. CYP105A1 from Streptomyces griseolus was first described as a herbicide-inducible sulfonylurea hydroxylase, but it is also able to convert other substrates such as vitamin D(3) . To extend the substrate pool of this interesting enzyme further, we screened a small diterpenoid compound library and were able to show the conversion of several resin acids.

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CYP11A1, a mitochondrial cytochrome P450, catalyzes the conversion from cholesterol to pregnenolone, the crucial step in the steroid hormone biosynthesis of mammals. It was shown in prior investigations, that the putative F-G loop of this enzyme is involved in membrane attachment. We produced different bovine CYP11A1 variants by rational protein design and could show that a deletion of 20 amino acids comprising parts of the F-G loop results in an enzyme with a three-fold increased solubility, the highest solubility of a CYP11A1 variant obtained so far.

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X-linked juvenile retinoschisis (RS) has previously been localized to a 7-8 cM interval between markers at (DXS43, DXS207) and (DXS274, DXS41). Our analysis of more than 300 meioses in two multigeneration RS families identified eight recombinant RS chromosomes and narrowed the RS locus to an interval between DXS987 and DXS443. Our data suggest the following order of loci: Xpter-DXS207-DXS987-([DXS418-DXS999], RS)-DXS443-DXS365-DXS274-Xcen.

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Alkaptonuria (AKU; McKusick no. 203500) is a rare autosomal recessive disorder caused by the lack of homogentisic acid oxidase activity. Patients excrete large amounts of homogentisic acid in their urine and a black ochronotic pigment is deposited in their cartilage and collagenous tissues.

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