ISSN:0892-6638    

DOI:10.1096/fasebj.1.1.3301495

出版商:Wiley    

年代:1987

数据来源: WILEY

摘要:

This paper provides a brief and selective review of recent work concerning the alterations in thermoregulation, cardiovascular, and respiratory physiology that occur as a function of different states of sleep and wakefulness. These state‐dependent changes in physiology were once regarded as a source of unwanted variance to be surgically or pharmacologically eliminated. The research paradigm championed by the work described here, however, requires that the endogenously generated state changes be recognized as potent independent variables influencing physiological control systems. Much evidence suggests that central monoamine‐containing neurons mediate many of the state‐dependent changes in thermoregulatory and cardiopulmonary physiology. A general conclusion emerging from these data is that studies of state‐dependent physiology are not merely descriptive; they are essential for a complete characterization of the cellular and molecular mechanisms underlying regulatory physiology.—Lydic, R. State‐dependent aspects of regulatory physiology.FASEB J.1: 6‐15; 1987.

ISSN:0892-6638    

DOI:10.1096/fasebj.1.1.3301498

出版商:Wiley    

年代:1987

数据来源: WILEY

摘要:

Certain general principles determine the biosynthesis of most biologically active peptides, including the opioid peptides, from large protein precursors. In almost all instances, the active peptide is embedded in the precursor flanked on both sides by pairs of basic amino acids. The first step in processing involves a trypsinlike enzyme, cleaving to the carboxyl terminus of basic amino acids, and leaving the active peptide with a basic amino acid on the carboxyl terminus. A carboxypeptidase B‐like enzyme then removes the remaining basic amino acid. It has been unclear whether any endopeptidases with trypsinlike activity are selective for one or another basic amino acid. Recently a soluble endopeptidase has been identified that can cleave to both the carboxyl and amino termini of basic amino acids. Enkephalin convertase (carboxypeptidase E, H) (EC 3.4.17.10) has considerable selectivity, and appears to be physiologically associated with the biosynthesis of enkephalin as well as a limited number of other neuropeptides. The turnover of opioid peptides and other neuropeptides is most effectively ascertained by measuring levels of mRNA either biochemically or by in situ hybridization. Striking dynamic alterations include a pronounced increase in levels of proenkephalin mRNA in the corpus striatum after blockade of dopamine receptors, but changes in opioid peptide mRNA after opiate addiction are less clear.—Costa, E.; Mocchetti, I.; Supattapone, S.; Snyder, S. H. Opioid peptide biosynthesis: enzymatic selectivity and regulatory mechanisms.FASEB J.1: 16‐21; 1987.

ISSN:0892-6638    

DOI:10.1096/fasebj.1.1.3111927

出版商:Wiley    

年代:1987

数据来源: WILEY

摘要:

Relating physiological variables on an organ system level to metabolic function within the intracellular environment has been exceedingly difficult because of a paucity of techniques. Most of the tools at our command necessitate either the removal or destruction of tissues before measurements can be made. Recently, NMR spectroscopy has been applied to several important questions relating organ system and cellular physiology. NMR has the distinct advantage of being noninvasive and nondestructive, allowing the investigator to make repetitive measurements of intracellular variables while manipulating experimental variables that are important on the organ system level. In this review we shall present several examples of such NMR investigations so that the reader will gain some appreciation of the potential of this relatively new technique. Cellular acid‐base homeostatic mechanisms, high‐energy phosphate metabolism, and regulation of anaerobic glycolysis will be discussed for such diverse cellular populations as mammalian brain, mammalian heart muscle, salamander skeletal muscle, amphibian skin, and invertebrate muscle. In addition, the role of phosphomonoesters and phosphodiesters in lipid metabolism for several tissues in different species will be evaluated.— Hitzig, B. M.; Prichard, J. W.; Kantor, H. L.; Ellington, W. R.; Ingwall, J. S.; Burt, C. T; Helman, S. I.; Koutcher, J. NMR spectroscopy as an investigative technique in physiology.FASEB J.1: 22‐31; 1987.

ISSN:0892-6638    

DOI:10.1096/fasebj.1.1.3301494

出版商:Wiley    

年代:1987

数据来源: WILEY

摘要:

Human lens γ‐crystallin obtained from the expression of a gene construct stably integrated into mouse L cells was incubated with ascorbate in the presence of iron and oxygen. The resulting oxidation of the γ‐crystallin led to more acidic species of this protein. These alterations were similar to the changes seen with aging in the human lens. The results suggest that oxidation of lens crystallins may be responsible for the changes seen on aging and cataract development and that ascorbate may contribute to these alterations.— Russell, P.; Garland, D; Zigler, J. S., Jr.; Meakin, S. O.; Tsui, L.‐C.; Breitman, M. L. Aging effects of vitamin C on a human lens protein produced in vitro.FASEB J.1: 32‐35; 1987.

ISSN:0892-6638    

DOI:10.1096/fasebj.1.1.3301496

出版商:Wiley    

年代:1987

数据来源: WILEY

摘要:

The effect of high concentrations of oxygen on cellular proteins was examined in hepatocytes isolated from rats exposed to 100% oxygen for 0, 24, 48, or 54 h. Previous studies have demonstrated that protein oxidation mediated by mixed‐function oxidase systems is accompanied by the formation of protein carbonyl derivatives that can be detected by the formation of protein hydrazone derivatives on treatment with 2,4‐dinitrophenylhydrazine (DNPH). In these studies the levels of DNPH‐reactive proteins increased steadily during 48 h of continuous oxygen treatment and then decreased to control levels by 54 h. Although the specific activity of two hepatic enzymes, glutamine synthetase and glucose‐6‐phosphate dehydrogenase, decreased during oxygen treatment, antibody titration of each enzyme indicated that the levels of immunological cross‐reactive protein either remained constant or increased slightly during 48 h of oxygen treatment. After 54 h of oxygen exposure the levels of immunologically cross‐reactive material were significantly reduced. These results suggest that exposure of rats to high concentrations of oxygen leads to the oxidative inactivation of enzymes and the accumulation of oxidized proteins that are subsequently degraded.— Starke, P. E.; Oliver, C. N.; Stadtman, E. R. Modification of hepatic proteins in rats exposed to high oxygen concentration.FASEB J.1: 36‐39; 1987.

ISSN:0892-6638    

DOI:10.1096/fasebj.1.1.2886388

出版商:Wiley    

年代:1987

数据来源: WILEY

摘要:

Incubation of mutant Niemann‐Pick C fibroblasts with low‐density lipoprotein (LDL) resulted in excessive internalization of lipoprotein and extensive cellular over‐accumulation of unesterified cholesterol. The uptake of LDL by the mutant cells appeared to occur through the classic LDL receptor pathway and internalized lipoprotein was processed in lysosomes. Lipoprotein uptake into mutant cells was associated with delays in the initiation of established cellular cholesterol homeostatic responses. Subcellular fractionation of mutant Niemann‐Pick C fibroblasts accumulating LDL‐cholesterol showed excess unesterified sterol to be localized in the light lysosome‐light membrane region of a Percoll gradient, and revealed that cholesterol storage was associated with a specific alteration in the normal profiles of lysosomal marker enzymes.— Pentchev, P. G.; Comly, M. E.; Kruth, H. S.; Tokoro, T; Butler, J.; Sokol, J.; Filling‐Katz, M.; Quirk, J. M.; Marshall, D. C.; Patel, S.; Vanier, M. T.; Brady, R. O. Group C Nieman‐Pick disease: faulty regulation of low‐density lipoprotein uptake and cholesterol storage in cultured fibroblasts.FASEB J.1: 40‐45; 1987.

ISSN:0892-6638    

DOI:10.1096/fasebj.1.1.3609608

出版商:Wiley    

年代:1987

数据来源: WILEY

摘要:

Microvilli isolated from 13762 mammary ascites tumor cells contain a major calcium‐sensitive protein (AMV‐p35) that can be isolated with microvillar microfilament cores prepared by Triton X‐100 extraction in the presence but not absence of calcium. AMV‐p35 can be readily purified from ethylene glycol bis(β‐aminoethyl ether)‐N,N,N‘,N‘‐tetraacetic acid extracts of the microfilament cores by chromatography on an anion exchange column, to which it does not bind. Immunoblot analysis indicates that AMV‐p35 is related to calpactin I, the pp60srctyrosine kinase substrate. In the presence of calcium, AMV‐p35 binds approximately 4 mol of chlorpromazine per mole of protein in a binding process showing apparent positive cooperativity, similar to calmodulin; however, in contrast to calmodulin, AMV‐p35 also binds phenothiazine in the absence of calcium.—Carraway, K. L., III; Liu, Y.; Puett, D; Carraway, K. L.; CarothersCarraway, C. A. Phenothiazine binding by a homolog of calpactin, the pp60srctyrosine kinase substrate.FASEB J.1: 46‐50; 1987.

ISSN:0892-6638    

DOI:10.1096/fasebj.1.1.3301497

出版商:Wiley    

年代:1987

数据来源: WILEY

摘要:

The photoaffinity reagent 8‐azido‐α‐[32P]ATP was used to label a protein of 170 kDa in membrane vesicle preparations from a highly multidrug‐resistant cell line, KB‐V1, but not from the drug‐sensitive parental cell line KB‐3‐1. The 170‐kDa labeled protein was immunoprecipitated with a monoclonal antibody (MRK‐16) to P glycoprotein. Both ATP and GTP inhibited labeling by 8‐azido‐α‐[52P]ATP. Labeling of P170 was not inhibited by 5 mM ADP, 5 mmribose‐5‐phosphate, or 100 μmvinblastine. These data directly demonstrate that P glycoprotein has a nucleotide‐binding site that could supply energy for drug transport.— Cornwell, M. M.; Tsuruo, T; Gottesman, M. M.; Pastan, I. ATP‐binding properties of P glycoprotein from multidrug‐resistant KB cells.FASEB J1: 51‐54; 1987.

ISSN:0892-6638    

DOI:10.1096/fasebj.1.1.2886389

出版商:Wiley    

年代:1987

数据来源: WILEY

摘要:

A soybean phospholipid mixture produced a concentration‐dependent enhancement of β subunit autophosphorylation of the detergent‐soluble, purified human placental insulin receptor. Although phosphatidylcholine, phosphatidylethanolamine, or phosphatidylserine also increased insulin receptor autophosphorylation, only phosphatidylinositol (PtdIns) stimulated to a similar extent as the phospholipid mixture. The effect of Ptdlns was biphasic, stimulating at low concentrations (75 μm), but having no stimulatory effect at high concentrations (1.0 mm). Phospholipids also stimulated the exogenous protein kinase activity of the insulin receptor toward histone H2B. Phosphorylation of PtdIns occurred with these purified insulin receptor preparations, but this activity was insulin‐independent, and the turnover number for PtdIns phosphorylation in the presence of soybean phospholipid was 1/220th as small as the turnover number for the autophosphorylating activity. These results suggest that although PtdIns can modulate the activity of the insulin receptor kinase, PtdIns phosphorylation itself is not directly involved in this regulation.—Sweet, L. J.; Dudley, D. T.; Pessin, J. E.; Spector, A. A. Phospholipid activation of the insulin receptor kinase: regulation by phosphatidyl‐inositol.FASEB J.1: 55‐59; 1987.

ISSN:0892-6638    

DOI:10.1096/fasebj.1.1.3038645

出版商:Wiley    

年代:1987

数据来源: WILEY