Resonance Raman evidence for tyrosine involvement in the radical site of galactose oxidase.

Resonance Raman data are reported for the redox-activated form of galactose oxidase from Dactylium dendroides. Excitation within the red (659 nm) and blue (457.9 nm) absorption bands leads to strong resonance enhancement of ligated tyrosine vibrational modes at 550, 1170, 1247, 1484, and 1595 cm-1. The ring mode frequencies are unusually low, indicating a decreased bond order in the ring. The spectra clearly differ in both frequencies and relative intensities from those characteristic of known aromatic pi-radicals. Enhancement of tyrosine ring modes on excitation within absorption bands previously associated with the presence of the radical in the active site suggests that the ligated tyrosine residue is present in the radical site and may stabilize this radical species through formation of a charge transfer complex. A dramatically different Raman spectrum is observed for the N3- adduct of galactose oxidase, exhibiting a single strong 1483 cm-1 feature. The intense visible-near IR absorption bands for galactose oxidase may derive from transitions within a charge transfer complex between an aromatic free radical and a tyrosine-copper complex.

Serum vitamin E levels in very low-birth weight infants receiving vitamin E in parenteral nutrition solutions.

Serum vitamin E levels were measured in 17 very low-birth weight infants in the first 2 wk of life, before and after the institution of intravenous vitamin E supplementation in a dosage of 4.5 mg/day, as a component of MVI Pediatric multivitamin preparation. Serum vitamin E levels were 0.22 +/- 0.16 (SD) mg/dl before supplementation, and rose to 2.55 +/- 0.65 (SD) mg/dl in nine infants more than 899 g birth weight, and rose to 3.68 +/- 0.70 (SD) mg/dl in six infants less than 900 g at birth. These postsupplementation serum vitamin E levels are in the range in which a reduction of incidence or severity of retinopathy of prematurity and intraventricular cerebral hemorrhage has been reported by others. No toxic effects of the preparation or of the increased vitamin E levels were found.

Translocation X;10 in a case of congenital acute monocytic leukemia.

Unusual cytogenetic findings were noted in the leukemic cells from a patient with congenital acute monocytic leukemia (AMol or M5, according to the FAB classification), whereas, the chromosomes of cultured skin fibroblasts were normal. G-banded karyotypes of leukemic cells showed an X-autosome translocation, 46,X,t(X;10)(Xpter----q13::10q11.2----qter)(10pter---- q11.2::Xq28----q13:: Xq28----qter). Review of reported cases of acute nonlymphocytic leukemia (ANLL) with rearrangements involving chromosomes #10 or X showed a high frequency of abnormalities of the short arm of #10 in myelomonocytic (M4) and monocytic (M5) leukemias, particularly in patients less than 2-yr-of-age. Although previously reported cases of ANLL in infants are predominantly of these types, the translocation observed in this case is unique. Fragile sites known to exist on chromosomes #10 and X are not associated with neoplasia and, except for Xq27-28, were not at the breakpoints of the case presented. The precise location of a human cellular oncogene recently identified on the X chromosome remains unknown.