The variant fetal hemoglobin F Texas I is abnormally acetylated.
Two related infants with indistinct slow-moving minor hemoglobin bands were detected by electrophoretic cord blood screening. The variant separated into a major and a minor band on isoelectric focusing (IEF), anion exchange chromatography (AEC), and high-performance liquid chromatography (HPLC). Analysis of the products of tryptic hydrolysis of the abnormal chain revealed a truncated A gamma T-1 peptide containing a glu----lys substitution at position 5, identifying the variant as Hb F Texas I. Microsequencing of the major early peak from AEC confirmed the substitution. However, gamma chains from the minor peak resisted Edman degradation and were shown to be acetylated by fast atom bombardment mass spectrometry (FABMS). Acetylation of HbF Texas I was nearly three times that of normal HbF measured in the same hemolysate, and this ratio remained constant for over 1 year in the proband. This represents the first demonstration of increased N alpha-acetylation of a variant fetal hemoglobin.
D000107:Acetylation; D000293:Adolescent; D000328:Adult; D002851:Chromatography, High Pressure Liquid; D004588:Electrophoresis, Cellulose Acetate; D005260:Female; D005312:Fetal Blood / Q000032:analysis; D005319:Fetal Hemoglobin / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D005431:Florida; D006580:Genetic Carrier Screening; D006455:Hemoglobins, Abnormal / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D007223:Infant; D008297:Male
D006455:Hemoglobins, Abnormal; C055794:hemoglobin F Texas; D005319:Fetal Hemoglobin