title: The pterin (bactopterin) of carbon monoxide dehydrogenase from Pseudomonas carboxydoflava.
abstract: Radioactively labeled carbon monoxide (CO) dehydrogenase has been obtained in good yield and purity from Pseudomonas carboxydoflava grown in the presence of [32P]phosphate. One enzyme molecule contained an average of 8.32 molecules of phosphate. The entire phosphate content was confined to 2 molecules of FAD and 2 molecules of a pterin. These were noncovalently bound. Molybdoenzyme cofactors could be extracted into N-methyl formamide; pterins were isolated by thin-layer chromatography. CO dehydrogenase contained a novel pterin, different from molybdopterin, which was also resolved in other bacterial molybdoenzymes. Therefore, it was tentatively named bactopterin. The characteristic features of bactopterin were as follows. A relative molecular mass, Mr, of 730 which was much greater than that of molybdopterin (330) (Mr values refer to molybdenum-free forms of the cofactors; presumably, the latter were also devoid of the sulfhydryl groups contained in the native compounds). A content of 2 molecules of phosphate/molecule compared to only 1 phosphate in molybdopterin. Bactopterin was three times less susceptible to air oxidation than molybdopterin. Native bactopterin was cleaved by perchloric acid into two phosphorous-containing fragments with Mr of 330 and 420. The smaller one is believed to be very similar to molybdopterin, the larger one was not a pterin but probably contained an aromatic structure.
mesh_terms: D000445:Aldehyde Oxidoreductases / Q000378:metabolism*; D002850:Chromatography, Gel; D002855:Chromatography, Thin Layer; D003067:Coenzymes; D003597:Cytosine Nucleotides; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D005559:Formamides / Q000494:pharmacology; D008667:Metalloproteins; D008970:Molecular Weight; D008982:Molybdenum / Q000032:analysis; D000090006:Molybdenum Cofactors; D009097:Multienzyme Complexes; D010472:Perchlorates / Q000494:pharmacology; D010710:Phosphates / Q000378:metabolism; D011549:Pseudomonas / Q000201:enzymology*; D011621:Pteridines / Q000032:analysis; D011622:Pterins / Q000032:analysis*
chemical_list: D000445:Aldehyde Oxidoreductases; D003067:Coenzymes; D003597:Cytosine Nucleotides; D005182:Flavin-Adenine Dinucleotide; D005559:Formamides; D008667:Metalloproteins; D008982:Molybdenum; D000090006:Molybdenum Cofactors; D009097:Multienzyme Complexes; D010472:Perchlorates; D010710:Phosphates; D011621:Pteridines; D011622:Pterins; C066895:molybdopterin cytosine dinucleotide; C022261:molybdopterin; C019823:carbon monoxide dehydrogenase; C002950:methylformamide