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S C Goheen

Publications and source records attributed to S C Goheen.

24 records · Page 2Linked to original sources
PubMed1980

Enhanced ratio of linoleic acid to arachidonic acid in erythrocyte phosphatidylcholine in rats during withdrawal from ethanol.

Male Sprague-Dawley rats were pair-fed for 8 weeks either an alcohol diet or a control diet made isocaloric with dextrose. Those on the alcohol diet were then fed the control diet for 3 days and both groups were killed. Analysis of the fatty acid composition of the various blood lipids showed that the relative level of 18:2 to 20:4 was significantly greater in the phosphatidylcholine fraction from erythrocytes of rats withdrawn from alcohol as compared to that from control animals. It has been suggested that in alcohol-fed animals the hepatic capacity to produce 20:4 from 18:2 is reduced. Therefore the increase in the ratio of 18:2/20:4 in erythrocyte phosphatidylcholine could serve as an index to detect the liver malfunction and to confirm recent chronic alcohol consumption.

Animals↗
PubMed1978

Raman spectroscopy of intact feline corneal collagen.

The Raman Spectrum of Collagen is presented from feline corneas which were fresh and intact, heat denatured, and incubated in 2H20. Two bands in the amide I region at approx. 1630 cm-1 and approx. 1660 cm-1 and two bands at ca. 1270 cm-1 and 1247 cm-1 in the amide III region appear in the Raman spectrum of fresh and heat denatured corneal collagen. The two amide III bands have been assigned to amide III vibrations in the polar and non-polar regions of the protein. Only one small amide I band at approx. 1650 cm-1 appears when corneas are treated with 2H2O suggesting that some portion of the Raman peaks in the amide I region for corneas in water is associated with water vibrations. Feline corneal collagen fibrils do not appear to dissociate appreciably upon heating to 70 degrees C. In fact, heated corneas appear structurally similar to corneas aged 30 h at 50 degrees C. We suggest that the swelling induced by heating and aging is predominantly caused by water being absorbed and remaining between the collagen fibrils, causing a slightly more disordered collagen matrix.

Animals↗
PubMed1976

Laser Raman spectroscopy of lipid-protein systems. Differences in the effect of intrinsic and extrinsic proteins on the phosphatidylcholine Raman spectrum.

Laser Raman spectroscopy is used to examine the interactions of intrinsic and extrinsic proteins with the lipid layer structure. The interactions of cytochrome c and cytochrome c oxidase with lipids have been well established by others using a variety of techniques. Cytochrome c is thought to act as an extrinsic membrane protein while cytochrome c oxidase is thought to act as an intrinsic membrane protein. The lipid-cytochrome c and lipid cytochrome c oxidase systems are used to assist in interpreting the spectral changes due to extrinsic and intrinsic protein interactions. The two types of proteins examined produced differential changes in the lipid hydrocarbon C-H stretch Raman modes for both dimyristoyl and dipalmitoyl phosphatidylcholine. The plasma proteins albumin and fibrinogen were also found to differentially affect the lipid hydrocarbon C-H stretch Raman nodes. These proteins appear to interact with lipids in an extrinsic manner different from that of cytochrome c.

Animals↗
PubMedDate not supplied

Electrospray ionization mass spectrometric characterization of acrylamide adducts to hemoglobin.

The most common procedure to identify hemoglobin adducts has been to cleave the adducts from the protein and characterize the adducting species, by, for example, derivatization and gas chromatography/mass spectrometry. To extend these approaches we used electrospray ionization mass spectrometry (ESI-MS) to characterize adducted hemoglobin. For this we incubated [14C]acrylamide with the purified human hemoglobin (type A0) under conditions that yielded high adduct levels. When the hemoglobin was separated by reversed-phase high-performance liquid chromatography (HPLC), 65% of the radioactivity copurified with the beta-subunit. Three adducted species were prominent in the ESI mass spectrum of the intact beta-subunit, indicating acrylamide adduction (i.e., mass increase of 71 Da) and two additional unidentified moieties with mass increments of 102 and 135 Da. Endoproteinase Glu-C digestion of the adducted beta-subunit resulted in a peptide mixture that, upon reversed-phase HPLC separation, provided several radiolabeled peptides. Using ESI-MS we identified these as the V91-101 and V102-122 peptides that represent the cysteine-containing peptides of the beta-subunit. These results provide definitive information on acrylamide-modified human hemoglobin and demonstrate that ESI-MS provides valuable structural information on chemically adducted proteins.

Acrylamides↗