Distribution of specific apolipoproteins determined by immunoblotting of baboon lipoproteins resolved by polyacrylamide gradient gel electrophoresis

A method for the quantitative assessment of apolipoprotein distributions among baboon serum lipoproteins is described. The method combines the precise and reproducible separation of lipoproteins by polyacrylamide gradient gel electrophoresis with the specificity of immunoblotting. The method permits the measurement of distributions for any apolipoprotein for which there are antibodies available. Radioactive secondary antibodies are used to expose X-ray film, and distributions are determined by densitometry. Absorbance is linearly related to both antigen and antibody concentrations. The method is reproducible, with the mean coefficient of variation calculated to be 0.118, and has a high repeatability (r ²=0.97). The immunoblotting method can be employed to measure the fine details of lipoprotein phenotypes as they are influenced by genotype and environment. This work was supported in part by grant HL28972 and Contract No. HV53030 from the National Institutes of Health.     

Apolipoprotein distribution in human lipoproteins separated by polyacrylamide gradient gel electrophoresis

The heterogeneity of serum lipoproteins (excluding very low density (VLDL) and intermediate density (IDL) lipoproteins) and that of lipoproteins secreted by HepG2 cells has been studied by immunoblot analysis of the apolipoprotein composition of the particles separated by polyacrylamide gradient gel electrophoresis (GGE) under nondenaturing conditions. The reactions of antibodies to apoA-I, apoA-II, apoE, apoB, apoD, and apoA-IV have revealed discrete bands of particles which differ widely in size and apolipoprotein composition. GGE of native serum lipoproteins demonstrated that apoA-II is present in lipoproteins of limited size heterogeneity (apparent molecular mass 345,000 to 305,000) and that apoB is present in low density lipoproteins (LDL) and absent from all smaller or denser lipoproteins. In contrast, serum apoA-I, E, D, and A-IV are present in very heterogeneous particles. Serum apoA-I is present mainly in particles of 305 to 130 kDa where it is associated with apoA-II, and in decreasing order of immunoreactivity in particles of 130-90 kDa, 56 kDa, 815-345 kDa, and finally within the size range of LDL, all regions where there is little detectable apoA-II. Serum apoE is present in three defined fractions, one within the size range of LDL, one containing heterogeneous particles between 640 and 345 kDa, and one defined fraction at 96 kDa. Serum apoD is also present in three defined fractions, one comigrating with LDL, one containing heterogeneous particles between 390 and 150 kDa, and one band on the migration front. Most of serum apoA-IV is contained in a band comigrating with albumin. GGE of centrifugally prepared LDL shows the presence of apoB, apoE, and apoD, but not that of apoA-I. However, the particles containing apoA-I, which, in serum, migrated within the LDL size range and as bands of 815 to 345 kDa, were recovered upon centrifugation in the d greater than 1.21 g/ml fraction. GGE of high density lipoproteins (HDL) indicated that most of apoA-I, A-II, and A-IV were present in lipoproteins of the same apparent molecular mass (390-152 kDa). ApoD tended to be associated with large HDL, and this was also significant for HDL apoE, which is present in lipoproteins ranging from 640 to 275 kDa. GGE of very high density lipoproteins (VHDL) presented some striking features, one of which was the occurrence of apolipoproteins in very discrete bands of different molecular mass. ApoA-II was bimodally distributed at 250-175 kDa and 175-136 kDa, the latter fraction also containing apoA-I.(ABSTRACT TRUNCATED AT 400 WORDS)     

Renin substrate in plasma of various mammalian species: electrophoresis on polyacrylamide gel.

The plasma of eight different species was subjected to electrophoresis on polyacrylamide gel, and the position of renin substrate was determined. There are considerable differences in the electrophoretic mobility of the renin substrates tested. Sheep substrate shows the slowest migration and mouse substrate the most rapid. The species tested appear to fall into two groups: slow-moving substrates occuring in the plasmas of sheep, cow, pig, and rabbit and fast moving substrates in man, dog, rat, and mouse. In most species only a single peak of renin substrate appeared, but in man and dog a minor peak was often observed in addition to the prominent major one. The classification of human renin substrate as an alpha-2-globulin is questioned.     

Analysis of purified tRNA species by polyacrylamide gel electrophoresis

Six purified amino acid acceptor tRNA species were examined by polyacrylamide gel electrophoresis. Small differences in migration were observed under conditions that preserve the conformation of tRNA. When tRNA was heated in the presence of either 10 mM acetate or EDTA at 60° a change in migration was observed for tRNA^Glu. No difference in migration was seen between Val-tRNA^Val and tRNA^Val. When tRNA was denatured by heating in 4M urea and applied to a gel containing the same amount of urea, all tRNA species migrated approximately the same distance with the exception of tRNA^{Leu V}, which showed an appreciable slower migration. From the difference in migration of tRNA^{Leu V} as compared to tRNA^Val and 5 S RNA, the difference in chain length between tRNA^Val and tRNA^{Leu V} was estimated to be approximately 9 nucleotides.     

Characterization of equine zona pellucida glycoproteins by polyacrylamide gel electrophoresis and immunological techniques.

This study was designed to explore the composition of the equine zona pellucida (EZP) by one- and two-dimensional polyacrylamide gel electrophoresis (1D- and 2D-PAGE), silver staining and immunoblotting techniques. Antral follicles palpable on frozen-thawed equine ovaries were aspirated with a needle and syringe, and the resultant follicular fluid, cellular material and oocytes were pooled. Oocytes were placed in Petri dishes, moved by narrow-bore pipette to droplets of phosphate-buffered saline (PBS) and mechanically cleaned of cumulus cells. The EZP from these collected oocytes was solubilized, and then analysed by 1D- and 2D-PAGE. Silver stained 2D-PAGE of the EZP revealed the presence of three EZP glycoprotein families of apparent molecular mass ranges of 93-120 kDa, 73-90 kDa and 45-80 kDa. Immunoblot analysis of EZP glycoproteins resolved by 2D-PAGE using rabbit antisera against pig zonae pellucidae (R alpha HSPZ) confirmed the presence of three EZP glycoprotein families and established the existence of common epitopes between equine and porcine ZP glycoproteins. Further immunodetection using 2D-PAGE-separated glycoproteins illustrated that the 45-80 kDa family is recognized by the monoclonal antibody R5, developed against the porcine ZP glycoprotein of molecular mass 55-120 kDa. Guinea-pig antiserum against endo-beta-galactosidase-treated rabbit ZP 55 kDa glycoprotein (R55K), which specifically recognizes the rabbit ZP glycoprotein with the lowest molecular mass, also recognized the EZP 45-80 kDa glycoprotein family. Guinea-pig polyclonal antisera developed against total heat-solubilized rabbit ZP (GP alpha HSRZ) recognized the 73-90 kDa EZP glycoprotein family exclusively. After heat solubilization and treatment of EZP with endo-beta-galactosidase to remove polylactosaminoglycans, silver stained 1D-PAGE again demonstrated the presence of three glycoproteins with apparent molecular masses of 60, 75 and 90 kDa. The partially deglycosylated 60 kDa equine glycoprotein is recognized on immunoblot by the monoclonal antibody R5; the 75 kDa EZP glycoprotein is recognized by GP alpha HSRZ; and all three EZP glycoproteins separated by 1D-PAGE are recognized by R alpha HSPZ. These data add further support to the concept of cross-species zona pellucida glycoprotein antigenicity.     

Polymorphism of hyaluronidase in serum from man, various mouse strains and other vertebrate species revealed by electrophoresis

Polymorphism of hyaluronidase (EC 3.2.1.35) was detected in the serum from 6 out of 20 vertebrate species by electrophoretic analysis. Electrophoresis was performed on a hyaluronan-containing polyacrylamide gel, that visualizes hyaluronidase activity upon incubation at acid pH. No hyaluronidase activity was detected in the sera of horse, swine, cattle, goat, sheep, rabbit, chicken, Triton alpestris, Triton palmatus, Triton vulgaris, pleurodeles, axolotl, eel and dog-fish. The 6 positive sera were from man, mouse, rat, Syrian hamster, dog and Triton cristatus. In each of these species, the electrophoretic banding pattern of hyaluronidase was different, as was the activity per unit volume of serum. Furthermore, in mice, the 12 strains analyzed could be divided into 3 groups, containing the following numbers of hyaluronidase bands; 8 (BALB/c/J, BALB/c/By, ICFW, SW, XVIInc/Z), 5 (DBA/2 Mrc Ico, DBA/2 Mrc Ico nu/nu, B10.D2/nSn), and 1 (C57B/Rho Ico, C57BL/6/By, C57BL/6/J Ico, C57BL/6/J Ico nu/nu). Human serum generally displayed only 1 band, although there was a 2nd faint band in a few cases and a 3rd in 1 case. Rat serum displayed 4 bands, Syrian hamster serum, 3, and dog and Triton cristatus serum, 1.     

Schistosoma mansoni: resolution and molecular weight estimates of tegument glycoproteins by polyacrylamide gel electrophoresis

Tegument samples of Schistosoma mansoni, extracted either by freezing and thawing or saponin, were fractionated in sodium dodecyl sulfate—polyacrylamide gel electrophoresis. The electrophoretic patterns varied if different extraction techniques were used. Lighter backgrounds and sharper bands were always observed with frozen and thawed preparations, although one of the major glycoprotein components and a PAS-positive diffuse material which migrates very rapidly were not extracted by this technique. The number of bands which could be identified by slab gel electrophoresis was approximately 25. Electrophoretic differences could be detected when teguments from male and female as well as young and adult parasites were compared. On the other hand, tegument preparations of 30-day parasites obtained from mice, rats, guinea pigs, and hamsters showed a remarkable similarity to each other.     

Comparative biochemical analysis of blood serum lipoproteins from human and various animal species

Lipid composition of blood serum and total lipids of low density lipoproteins (LDL) and high density lipoproteins (HDL2 and HDL3) were studied in human (donors, patients with ischemic heart disease, bronchial asthma, chronic obstructive bronchitis, as well as with a combined pathology), in mammals predisposed to atherosclerosis (pig, rabbit) and resistant to atherosclerosis (rat, mink, Arctic fox), in birds (hen, pigeon), in teleost fish (white fish, pikeperch, pike, bream, burbot) and cartilaginous fish (sturgeon, housen). It has been established that the most enriched in lipids is the blood serum of animals, particularly of cartilaginous fish. Twice lower is the lipid content in blood serum of donors than of animals. However, in the vascular, bronchial-pulmonary, and combined human pathologies the lipid level rises statistically significantly. In human and in animals predisposed to atherosclerosis the main mass of lipid is located in LDL, whereas in animals resistant to this disease--in HDL. The ratio of the human lipid content in LDL/HDL increases from 1.4 (in donors) to 2.7 in pathological states--in ischemic heart disease and its combination with chronic obstructive disease. In animals, a decrease of this ratio is noted from 1.0 to 0.2 in cartilaginous fish. By the example of one taxon (fish) there is established a regularity that indicates that evolution of lipoproteins occurred with an increase of the lipid amount in the "younger" LDL and with a decrease of concentration of the "colder" HDL.     

The molecular weight determination of proteins and glycoproteins of RNA enveloped viruses by polyacrylamide gel electrophoresis in SDS

The apparent molecular weights for glycoproteins of four RNA enveloped viruses — influenza virus, NDV, VSV and AMV, calculated relative to protein standards depend upon the percent of acrylamide used. Such anomaly is not observed for other proteins of these viruses. The irregular behaviour of glycoproteins resulted from their lesser capacity to bind SDS.     

盘状聚丙烯酰胺凝胶电泳法分离血清蛋白实验的几点改进

对盘状聚丙烯酰胺凝胶电泳法分离血清蛋白实验提出了几点改进,以满足本科生实验的要求。实验主要比较和分析了两种封胶方法（原胶布封胶与改进的琼脂糖封胶）和两种染色方法（原考马斯亮蓝染色法与改进的考马斯亮蓝染色法）对凝胶分离血清蛋白实验的影响。结果显示,改进的盘状聚丙烯酰胺凝胶电泳法是一种灵敏、快速、简便、安全、分辨率高的实验方法。结论：改进的盘状聚丙烯酰胺凝胶电泳法分离血清蛋白实验非常适合本科生实验。     

Content of the main lipid components in blood serum lipoproteins of human and of various animal species

Using precipitation method, low-density (LDL) and high-density (HDL2 and HDL3) lipoproteins were isolated from blood serum of human (donors, patients with ischemic heart) diseases--IHD, with bronchial asthma--BA, with chronic obstructive bronchitis--COB), of mammals predisposed (pig, rabbit) and resistant (rat, mink, Arctic fox) to atherosclerosis, of birds (hen, pigeon), of bony fish (trout, white-fish, pike-perch, pike, bream, burbot), and of cartilaginous fish (sturgeon, white sturgeon). From each lipoprotein group, lipids were extracted, separated by thin-layer chromatography, and analyzed quantitatively by the spectrophotometric method. In phosphatidylcholine and HDL2 cholesterol esters, bound fatty acids (FA) were determined by the method of gas-liquid chromatography. The main amount of total cholesterol has been established to be concentrated in human LDL, especially in the cases of IHD, and in LDL in mammals predisposed to atherosclerosis. In mammals resistant to atherosclerosis and in fish the almost entire cholesterol was revealed in HDL. The phospholipid content in HDL was lower in patients with pathologies and in mammals predisposed to atherosclerosis, while the highest content--in fish and mammals resistant to atherosclerosis. In homoiothermal animals and in human the main FA amount in HDL was represented by the omega6-series. Acids of the omega3-series amounted to a negligible percentage, especially in IHD. On the contrary, the HDL FA composition of poikilothermal animals (fish) had a very high content of polyunsaturated FA of the omega3-series. A conclusion is made that composition of lipid components in animal lipoproteins by the example of several studied species and of human has a non-stable character and is submitted to changes. Their most pronounced modifications with a negative trend took place in human LDL and HDL in IHD.