title: Synthesis of substrate analogs of methyltransferases in the vitamin B(12) biosynthetic pathway and characterization of their enzymatic products.
abstract: The specificity toward substrate analogs of the first two methyltransferases in the vitamin B(12) biosynthetic pathway was probed with 15 synthetic porphyrinogens. Several novel methylated chlorins and isobacteriochlorins were isolated and characterized, suggesting the same methylation sequence C-2>C-7>C-20 as for the natural substrate, uro'gen III. The results allow us to narrow down possible structural requirements concerning substrate recognition by the methyltransferase enzymes.
authors.affiliation: Department of Chemistry, Texas A&M University, PO Box 30012, College Station, TX 77842-3012, USA.
authors.forename: Clotilde
authors.initials: C
authors.lastname: Pichon-Santander
authors.forename: Patricio J
authors.initials: PJ
authors.lastname: Santander
authors.forename: A Ian
authors.initials: AI
authors.lastname: Scott
mesh_terms: D009682:Magnetic Resonance Spectroscopy / Q000379:methods / Q000592:standards; D008745:Methylation; D008780:Methyltransferases / Q000737:chemistry*; D015394:Molecular Structure; D011165:Porphyrinogens / Q000138:chemical synthesis* / Q000737:chemistry*; D011166:Porphyrins / Q000737:chemistry / Q000302:isolation & purification; D012015:Reference Standards; D012680:Sensitivity and Specificity; D013237:Stereoisomerism; D013379:Substrate Specificity; D014805:Vitamin B 12 / Q000096:biosynthesis*
chemical_list: D011165:Porphyrinogens; D011166:Porphyrins; C452434:isobacteriochlorin; C006969:chlorin; D008780:Methyltransferases; D014805:Vitamin B 12