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J D Hayes

Publications and source records attributed to J D Hayes.

161 records · Page 9Linked to original sources
PubMed1983

Rat liver glutathione S-transferases. A study of the structure of the basic YbYb-containing enzymes.

A purification scheme was devised that resulted in the resolution of a number of basic glutathione S-transferases from rat liver, three of which contained two subunits of molecular mass 23500 Da (i.e. Yb monomers). These were identified as transferases D, C and A by their elution positions from CM-cellulose and their specific activities towards a variety of substrates. Hybridization, immunotitration and peptide 'mapping' experiments demonstrated that transferases D, C and A comprise Yb2Yb2, Yb1Yb2 and Yb1Yb1 subunits.

Amino Acids↗
PubMed1983

Lecithin: cholesterol acyltransferase in Down's syndrome.

Based on earlier reports indicating that Down's syndrome may represent an atheroma-free human model, two groups of institutionalized subjects were compared with respect to various parameters of their plasma lipid transport system. One group of subjects was comprised of Down's syndrome subjects and the second, a group of mentally retarded individuals. Parameters measured included plasma cholesterol, triglyceride, HDL-cholesterol, apolipoprotein levels (A-I, B, C-III, and E), lecithin:cholesterol acyltransferase (LCAT) activity, body mass and blood pressure. Statistical analyses indicated no significant differences between the two groups except for the lower fractional rate of cholesterol esterification (% cholesterol esterified per hour, p = 0.0049) in the Down's syndrome subjects. Adjustment for the effects of body mass and age revealed no other significant differences between the two groups except for a lower molar rate of esterification (nmol cholesterol esterified X h-1 X ml-1, p less than 0.0063) in the Down's syndrome subjects. Additional differences between the two groups were revealed by partial correlational analyses of LCAT activity with the measured parameters or ratios of these parameters which suggests that the composition and/or metabolism of lipoproteins may differ between these two groups. Whether the lower LCAT activity and the other differences reflected by the correlational analyses contribute to the decreased incidence of atherosclerotic lesions in Down's syndrome remains to be elucidated.

Adolescent↗
PubMed1982

Purification and characterization of three forms of glutathione S-transferase A. A comparative study of the major YaYa-, YbYb- and YcYc-containing glutathione S-transferases.

Rat liver glutathione S-transferases have previously been defined by their elution behaviour from DEAE-cellulose and CM-cellulose as M, E, D, C, B, A and AA. These enzymes are dimeric proteins which comprise subunits of mol.wt. 22 000 (Ya), 23 500 (Yb) or 25 000 (Yc). Evidence is presented that YaYa protein, one of two previously described lithocholate-binding proteins which exhibit transferase activity, is an additional enzyme which is not included in the M, E, D, C, B, A and AA nomenclature. We therefore propose that this enzyme is designated transferase YaYa. Transferases YaYa, C, A and AA have molecular weights of 44 000, 47 000, 47 000 and 50 000 respectively and each comprises two subunits of identical size. These enzymes were purified to allow a study of their structural and functional relationships. In addition, transferase A was further resolved into three forms (A1, A2 and A3) which possess identical activities and structures and appear to be the product of a single gene. Transferases YaYa, C, A and AA each had distinct enzymic properties and were inhibited by cholate. The recently proposed proteolytic model, which attributes the presence of multiple forms of glutathione S-transferase activity to partial proteolysis of transferase AA, was tested and shown to be highly improbable. Peptide maps showed significant differences between transferases YaYa, C, A and AA. Immunotitration studies demonstrated that antisera raised against transferases YaYa and C did not precipitate transferase AA.

Animals↗
PubMed1981

A study of the structures of the YaYa and YaYc glutathione S-transferases from rat liver cytosol. Evidence that the Ya monomer is responsible for lithocholate-binding activity.

The two dimeric lithocholic acid-binding proteins previously identified as ligandin (YaYa) and glutathione S-transferase B (YaYc) were isolated from rat liver cytosol. These proteins have molecular weights of 44000 and 47000 respectively. The recovery of these two proteins from liver was not affected by the addition of the proteinase inhibitor Trasylol. No spontaneous interconversion between these two proteins was observed on storage. YaYa and YaYc proteins yielded peptides of identical molecular weight after limited digestion with Staphylococcus aureus V8 proteinase. Analytical and preparative tryptic-digest peptide 'maps' showed that all the soluble peptides obtained from YaYa protein were also recovered from YaYc protein. Approximately six extra soluble peptides, which were not recovered from YaYa protein, were obtained from the tryptic digest of YaYc protein. Subdigests of the insoluble tryptic-digest 'cores' also resulted in the recovery of identical peptides from both proteins. Evidence is presented that the Ya subunit possessed by both proteins is identical; glutathione S transferase B is a hybrid of ligandin and glutathione S-transferase AA. The Ya monomer is responsible for lithocholate binding.

Animals↗
PubMed1980

Cholic acid binding by glutathione S-transferases from rat liver cytosol.

Cholic acid-binding activity in cytosol from rat livers appears to be mainly associated with enzymes having glutathione S-transferase activity; at least four of the enzymes in this group can bind the bile acid. Examination of the subunit compositions of different glutathione S-transferases indicated that cholic acid binding and the ability to conjugate reduced glutathione with 1,2-dichloro-4-nitrobenzene may be ascribed to different subunits.

Animals↗
PubMed1979

Identification of two lithocholic acid-binding proteins. Separation of ligandin from glutathione S-transferase B.

1. Two lithocholic acid-binding proteins in rat liver cytosol, previously shown to have glutathione S-transferase activity, were resolved by CM-Sephadex chromatography. 2. Phenobarbitone administration resulted in induction of both binding proteins. 3. The two proteins had distinct subunit compositions indicating that they are dimers with mol.wts. 44 000 and 47 000. 4. The two lithocholic acid-binding proteins were identified by comparing their elution volumes from CM-Sephadex with those of purified ligandin and glutathione S-transferase B prepared by published procedures. Ligandin and glutathione S-transferase B were eluted separately, as single peaks of enzyme activity, at volumes equivalent to the two lithocholic acid-binding proteins. 5. Peptide 'mapping' revealed structural differences between the two proteins.

Animals↗
PubMed1977

Partial purification of two lithocholic acid-binding proteins from rat liver 100 000g supernatants.

1. The partial purification of two lithocholic acid-binding proteins from liver 100 000g supernatants is described. 2. Gel-filtration, (NH4)2SO4 fractionation, Ca3(PO4)2 fractionation and ion-exchange chromatography were used. 3. Both proteins exhibited glutathione S-transferase activity; one may be the non-specific anion-binding protein ligandin. 4. Glutathione S-transferase activity of one of the binding proteins was inhibited by lithocholic acid.

Animals↗
PubMed1974

Fire in the OR.

Explore the source record for details and available documents.

Accident Prevention↗
PubMedDate not supplied

Vascular ring anomaly.

Congenital vascular ring anomalies frequently present to the pediatric otolaryngologist with symptoms of tracheoesophageal compression. One such case is reported and the literature reviewed. The role of the otolaryngologist in the diagnosis and management of congenital vascular ring anomalies is discussed.

Aorta, Thoracic↗
PubMedDate not supplied

The heparin binding domain of insulin-like growth factor binding protein (IGFBP)-3 increases susceptibility of IGFBP-3 to proteolysis.

IGFBP-3 proteolysis clears IGFBP-3 from body fluids and increases IGF bioavailability. As shown here, native human IGFBP-3 was cleaved by proteases in media conditioned by hamster and insect cells. This proteolysis was less pronounced for IGFBP-3 containing a mutated heparin binding domain, and was prevented by purifying IGFBP-3 on an IGF-I affinity column in the presence of 2 M sodium chloride, suggesting that the responsible protease(s) binds the IGFBP-3 heparin binding domain. To determine if any human proteases act this way, we first studied plasma prekallikrein since it can copurify with IGFBP-3, and found: 1) [125]IGFBP-3 binds to prekallikrein immobilized either on nitrocellulose or on immunocapture plates; 2) the IGFBP-3 heparin binding domain participates in forming the IGFBP-3/prekallikrein complex; 3) the binary IGFBP-3/prekallikrein complex can bind IGF-I to form a ternary complex; and 4) activation of prekallikrein to alpha-kallikrein by Factor XIIa resulted in proteolysis of bound IGFBP-3. This work suggests: 1) cleavage of IGFBP-3 by a protease may be aided by the ability of the protease zymogen to directly bind the IGFBP-3 heparin binding domain; and 2) direct binding of protease zymogens to IGFBP-3 may explain some instances where IGFBP-3 is preferentially proteolyzed in the presence of other IGFBPs.

Amino Acid Sequence↗
PubMedDate not supplied

Smoking among women: a life cycle perspective on which to base prevention/cessation interventions.

Smoking among women continues at high rates despite the severe health consequences that may result for these women and for their children. A conceptual model identifying core factors that influence the onset and development of smoking and its cessation and continued abstinence was developed and provides a framework for understanding women's smoking behavior. This model examines a number of smoking-related health consequences that occur during the woman's life cycle and proposes suggestions for assessment and nursing intervention.

Attitude to Health↗