Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0009443 (cold)
 92,137 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two forms (M1 and M2) of the membrane-bound acid protease of Aspergillus oryzae have been purified by extraction with Triton X-100, washing with cold acetone, and repeated gel filtration on Bio-Gel A-15 m in the presence and absence of Triton X-100. The purified membrane enzymes, M1 and M2, moved as a single band in acrylamide gel electrophoresis and had apparent molecular weights of 150 000 and 60 000, respectively, as estimated by sodium dodecyl sulfate/acrylamide gel electrophoresis. These two membrane enzymes activated bovine pancreatic trypsinogen and had the same pH optima in the acid pH range. They immunologically cross-reacted with each other and with an extracellular acid protease from A. oryzae, and contained carbohydrate, ranging from 52.5 to 80.5% and comprising three hexoses, glucose, galactose, and mannose. While these catalytic, chemical and immunological properties are similar to those of the extracellular acid protease from A. oryzae, both membrane enzyme differed in their hydrophobic properties from external enzymes. Thus they are activated by the detergent Triton X-100 and some polar lipids.
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PMID:Purification and characterization of the two molecular forms of membrane acid protease from Aspergillus oryzae. 2 77

Shellfish glycogen was cross-linked by treatement with cyanogen bromide followed by 1,6-diaminohexane. The resulting, insoluble product efficiently adsorbed Helix pomatia alpha amylase [(1 linked to 4)-alpha-D-glucan glucanohydrolase] from crude solutions of the enzyme at 0 degrees, but only poorly at higher temperatures. A method was developed for the purification of Helix pomatia alpha amylase involving formation of an enzyme-adsorbent complex in the cold and recovery of the alpha amylase by suspending the washed complex in buffer at 37 degrees. After chromatography of the desorbed alpha amylase on a column of Bio-Gel P-60, the enzyme was homogenous as judged by poly(acrylamide)-gel electrophoresis. An overall purification of 360-fold was achieved with a recovery of 35%.
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PMID:A purification of Helix pomatia alpha amylase involving a novel affinity-binding procedure. 30 87

The gelation induced by warming (to 25 degrees C) the 100,000 g supernatant fraction (extract) of HeLa cells lysed in a buffer containing sucrose, ATP, DTE, EGTA, imidazole, and Triton X-100 was studied in the presence of myosin and heavy meromyosin (HMM). Myosin mixed with extract induces shrinkage of the gel, but jelled extract or myosin alone does not shrink. In the concentration range, 0.14-1.04 mg/ml of myosin, the degree of shrinkage is roughly proportional to the concentration of myosin. Supplementa MgCl2 also promotes shrinkage. HMM (0.4-0.8 mg/ml) can inhibit gel formation by extract in tubes or floated on a sucrose cushion. Gel electrophoresis of gels shrunken by added myosin or electrophoresis of the proteins which can be sedimented from extract after incubation in the presence of HMM indicate that both myosin and HMM interfere with the changes in sedimentability of the high molecular weight protein (HMWP) thought to participate (together with actin) in gel formation in HeLa cell extracts (R. R. Weihing, 1976. J. Cell Biol. 71:303-307). These results, together with previous results showing that actin is present and that HMWP is enriched in the plasma membrane fraction of HeLa cells (R. R. Weihing, 1976. Cold Spring Harbor Conf. Cell Proliferation. 3:671-684), point to the possibility of dynamic changes in the interactions of HMWP or myosin with actin in processes of movement occurring at the cell surface.
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PMID:Effects of myosin and heavy meromyosin on actin-related gelation of HeLa cell extracts. 33 81

It was possible to prolong the herpes free intervals with combined chemotherapy with 0,3% Ethyl-desoxyuridine (EDU)-Gel during the acute phase and continued application of 0,2% Jodo-desoxyuridine (IDU)-ointment with 1,8% DMSO. The combined chemotherapy did not improve the effect of the treatment with EDU alone in respect of the duration of skin lesions. In 5 out of 8 patients with recurrent cold sores and in 3 out of 10 patients with genital herpes further immunotherapeutical measures were not necessary. The results indicate that beside the chemotherapy of the recurrences with monotherapy a continuous chemoprophylaxis can be successful in patients with recurrent herpes simplex.
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PMID:[Combined chemotherapy of herpes simplex infections of the skin]. 52 71

It has been found that a high-speed supernatant fraction from Xenopus oocytes extracted in the cold will form a clear, solid gel upon warming. Gel formation occurs within 60 min at 18 degrees-40 degrees C, and is, at least initially, temperature reversible. Gelation is strictly dependent upon the addition of sucrose to the extraction medium. When isolated in the presence of ATP, the gel consists principally of a 43,000-dalton protein which co-migrates with Xenopus skeletal muscle actin on SDS-polyacrylamide gels, and a prominent high molecular weight component of approx. 250,000 daltons. At least two minor components of intermediate molecular weight are also found associated with the gel in variable quantities. Actin has been identified as the major consituent of the gel by ultrastructural and immunological techniques, and comprises roughly 47% of protein in the complex. With time, the gel spontaneously contracts to form a small dense aggregate. Contraction requires ATP. In the absence of exogenous ATP, a polypeptide which co-migrates with the heavy chain of Xenopus skeletal muscle myosin becomes a prominent component of the gel. This polypeptide is virtually absent from gels which have contracted in ATP-containing extracts. It has also been found that Ca++ is required for gelation in oocyte extracts. At both low and high concentrations of Ca++ (defined as a ratio of Ca++/EGTA in the extraction medium), gelation is inhibited.
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PMID:Actin in Xenopus oocytes. 56 81

Human leukocytes stimulated in vitro release leukocytic pyrogen (LP), a protein which is the mediator of fever. In order to study human leukocytic pyrogen, we attempted to purify this molecule from the large quantity and variety of proteins which are present in leukocyte supernates. Human peripheral leukocytes were stimulated in vitro by phagocytosis of killed staphylococci, and several methods were used to isolate the pyrogen protein. First, using isoelectric focusing, it was found that crude leukocyte supernates contained two molecular species of LP which were separable by precipitation in cold alcohol. Isoelectric focusing, although used for confirmation of the molecular homogeneity of LP, could not be employed as a preparative purification technique. Following alcohol precipitation, human LP was chromatographed on ion-exchange materials at various pH with modest recovery of initial activity but marked increase in specific activity. Gel-filtration was also employed and yielded partially purified LP. When alcohol precipitation was combined with ion exchange at alkaline pH and followed by gel-filtration, resulting LP preparations contained 5 or 6 contaminating proteins. These results demonstrate that human LP can be partially purified from the large quantity and variety of proteins present in crude leukocyte supernates and during purification procedures, the pyrogen did not change in either molecular weight or isoelectric point. This work provides reliable techniques for initial purification of human LP.
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PMID:Partial purification of human leukocytic pyrogen. 61 7

Electrophoresis of microtubule preparations purified from calf brain by repeated cycles of assembly and disassembly shows that they contain many proteins in addition to alpha- and beta-tubulin. These additional proteins constitute about 17% of the total material present after five cycles of assembly and disassembly. Both one-dimensional and two-dimensional (P.H. O'Farrell (1975), J. Biol. Chem. 250, 4007) electrophoretic techniques have been used to characterize them. They can be divided into two groups: one that contains proteins which remain in constant quantitative ratio to tubulin during the purification cycles, and one composed of proteins which are removed during purification, although inefficiently. Gel-filtration chromatography of cold-depolymerized microtubule preparations yields a polydisperse fraction of high molecular weight containing most of the non-tubulin proteins. This fraction contains flexible filaments about 100 A in diameter similar to those reported by R.A.B. Keats and R.H. Hall ((1975), Nature (London) 247, 418). It is suggested that these fibers are neurofilaments, and that they may be the major source of the group of inefficiently removed proteins.
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PMID:Separation and characterization of microtubule proteins from calf brain. 92 53

The temperature-dependent assembly and the interaction of Acanthamoeba contractile proteins have been studied in a crude extract. A cold extract of soluble proteins from Acanthamoeba castellanii is prepared by homogenizing the cells in a sucrose-ATP-ethyleneglycol-bis-(beta-aminoethyl ether) N,N'-tetraacetic acid buffer and centrifuging at 136,000 g for 1 h. When this supernate of soluble proteins is warmed to room temperature, it forms a solid gel. Upon standing at room temperature, the gel slowly contracts and squeezes out soluble components. The rates of gelation and contraction are both highly temperature dependent, with activation energies of about 20 kcal per mol. Gel formation is dependent upon the presence of ATP and Mg++. Low concentrations of Ca++ accelerate the contractile phase of this phenomenon. The major protein component of the gel is actin. It is associated with myosin, cofactor, a high molecular weight protein tentatively identfied as actin-binding protein, and several other unidentified proteins. Actin has been purified from these gels and was found to be capable of forming a solid gel when polymerized in the presence of ATP, MgCl3, and KCL. The rate of purified actin polymerication is very temperature dependent and is accelerated by the addition of fragments of muscle actin filaments. These data suggest that Acanthamoeba contractile proteins have a dual role in the cell; they may generate the forces for cellular movements and also act as cytoskeletal elements by controlling the consistency of the cytoplasm.
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PMID:The role of actin in the temperature-dependent gelation and contraction of extracts of Acanthamoeba. 103 Jul 5

Further studies are reported on the existence of a sensitizing factor in plasma of hypertensive subjects, which increases the vascular sensitivity to pressor agents when injected iv into nephrectomized rats. Plasma samples from normotensive subjects, patients with malignant hypertension, normotensive dogs, and dogs with experimental renovascular hypertension were fractionated on Bio-Gel P-10 columns after cold acetone precipitation, and on DEAE-cellulose columns eluted with sodium chloride and pH gradients. The effect of the various fractions on the vascular sensitivity to angiotensin was tested utilizing nephrectomized rats. The sensitizing activity was found only in fractions obtained from plasma of hypertensive patients and dogs and it was concentrated primarily in three fractions. Th results suggest that the sensitizing factor is negatively charged at neutral pH and it could be a polypeptide or a small protein.
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PMID:Further studies on the existence of a sensitizing factor to pressor agents in hypertension. 115 Aug 66

Plasma from cattle dying from infection with Babesia argentina formed a cold precipitable gel when stored at 4 degrees C. Immunodiffusion and electrophoresis showed the soluble phase of the gel to consist mainly of a fibrinogen-like protein with small amounts of other plasma proteins. Gel filtration and specific clotting assays demonstrated a wide molecular weight spectrum of fibrinogen-like proteins, most of which appeared to be soluble fibrin in either monomer or complex forms. The possibility that proteolytic enzymes might be responsible for the formation of the gel is discussed.
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PMID:A cold precipitable fibrinogen complex in the plasma of cattle dying from infection with Babesia argentina. 122 Mar 58


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