The gender-specific apolipoprotein E genotype influence on the distribution of lipids and apolipoproteins in the population of Rochester, MN. I. Pleiotropic effects on means and variances.

The influences of the apolipoprotein E (Apo E) polymorphism and of gender on the distributions of plasma levels of total cholesterol (Total-C), 1n triglycerides (1n Trig), HDL cholesterol (HDL-C), and apolipoproteins AI (Apo AI), AII (Apo AII), 1n E (1nApo E), B (Apo B), CII (Apo CII), and 1n CIII (1nApo CIII) were studied in 507 unrelated individuals representative of the adult population of Rochester, MN. Apo E genotypes influenced both phenotypic level and intragenotype phenotypic variability. The mean levels of six of the nine traits were influenced significantly by Apo E genotype. Intragenotype variability in eight of the nine traits was significantly different among Apo E genotypes. These effects were estimated separately in males and females. The contribution of allelic variation in the Apo E gene to the definition of the multivariate mena and variance of the lipid and apolipoprotein hyperspace was evaluated. These findings were used to demonstrate how heterogeneity of risk-factor-trait variance among genotype/gender-specific subgroups of the population at large may influence the evaluation of risk of coronary artery disease.     

Kinetics of lipids and lipoproteins with determination of the recovery rate in the non-steady state following plasma, membrane filtration and dextran sulfate adsorption apheresis in hypercholesterolemia

In the work presented here, the efficiency of the following techniques was determined in the period 1983-1988 with respect to the elimination of lipids, lipoproteins and apoproteins in patients with severe hypercholesterolemia; firstly with plasmapheresis, then with membrane-filtration apheresis, and recently with dextran sulfate adsorption apheresis. Furthermore, the loss resulting from removal by apheresis in lipids, lipoproteins and apoproteins was calculated by means of a single-compartment model from pool size and recovery rates. It could be shown that the individual lipids (TG, CH, LDL-CH, P) in the serum as well as in the lipoprotein fractions (VLDL, LDL, HDL) attained new steady states at differing rates, the recovery times for cholesterol being the longest, those of HDL-CH and apoproteins AI, AII, CII, CIII and E the shortest. The absolute replacement in "mg/kg BW/d" was 35 for beta-lipoprotein, 18-22 for total-CH, 13-17 for LDL-CH, 10-12 for apoprotein B; for the antiatherogenic lipids HDL-CH it was 1.72-2.7 mg/kg BW/d; for alpha-lipoprotein 14-23 mg/kg BW/d; for apoprotein HDL 16-19 mg/kg BW/d. The recovery rates for anti- and atherogenic lipids for women with heterozygous FH were higher than for men with FH. Rates of 0.235; 0.510 and 0.183 mg/kg BW/d were measured for CII, CIII and apoprotein E respectively. Dextran sulphate adsorption apheresis (Kaneka) is a more specific method for eliminating LDL-CH and apoprotein B than plasmapheresis and membrane filtration apheresis. The amounts removed in LDL and apo B with the Kaneka technique are largely identical with those taken out by membrane filtration. Larger relative and absolute recovery rates for LDL-CH, total-CH and apo B were found after Kaneka's DSA-apheresis, which may be explained by the more specific removal in LDL-CH and apo B.     

Human apolipoproteins AI, AII, CII and CIII. cDNA sequences and mRNA abundance

The structure and function of the genes encoding the polypeptide components of plasma lipoproteins are of interest because of the central role they play in the regulation of lipid metabolism. We have now completed our previous studies on the human apoAI gene and furthermore isolated and sequenced cDNA clones for apoAII , CII and CIII. The nucleotide sequences show the signal peptides of apoAII , CII and CIII to be 18, 22 and 20 amino acids in length, respectively, and in addition that prepro apoAII bears a classical propeptide structure of 5 amino acids. The amino acid homology detected between apoCII and pro- apoAI is discussed, as is the gene arrangement of the 5' non-coding region of apoAI mRNA. The relative liver mRNA levels of the 4 apolipoproteins analysed in this study have been estimated and compared with their corresponding plasma products. The data reported here provide an essential basis for further studies of structural and functional alleles of apo AI, AII, CII and CIII genes.     

Expression of the human serum apolipoprotein AI and AII genes in Xenopus laevis oocytes. Lipid-associated secretion of gene products

The two major apolipoproteins of plasma high-density lipoproteins (HDL) are apolipoprotein AI (apo AI) and AII (apo AII). The apo AI and the correctly oriented apo CIII genes separated by 2.6 kb were obtained by fusion of two human lambda-genomic clones. The apo AII gene was isolated as a 3 kb clone. These apolipoprotein genes have been injected independently and together into Xenopus laevis oocytes and their expression studied. Both apolipoprotein genes were transcribed and translated into their preproforms and processed in Xenopus laevis oocytes to their proforms. They were secreted into the medium associated with newly synthesized phospholipids and neutral lipids as particles floating in the high-density lipoprotein range between 1.12 and 1.21 g/ml. Secreted apo AI is associated mainly with newly synthesized phosphatidylethanolamine and little triglyceride, apo AII with phosphatidylethanolamine, lysophosphatidylethanolamine and neutral lipids. Simultaneous injection of the apo AI and apo AII genes led to the secretion of both apoproteins which separated into two bands during CsCl-density gradient centrifugation. The heavier particles were associated with proapo AI and AII, phosphatidylethanolamine (greater than 90%) and traces of lysophosphatidylethanolamine as lipid components. Proapo AII was immunoprecipitated from the less dense fraction and found to be mainly associated with lysophosphatidylethanolamine. Radiolabelled newly synthesized apolipoproteins in secreted particles were characterized by immunoprecipitation after delipidation of the secreted lipoprotein particles. The oocyte-system proved very suitable for studies of the expression of serum apolipoprotein genes, the assembly of the apolipoproteins with specific lipids to lipoprotein particles and their secretion.     

A DNA polymorphism of the apoprotein AII gene in hypertriglyceridaemia

Summary A polymorphism of the apolipoprotein AII gene (on chromosome 1) was investigated using genomic hybridisation analysis. The two common alleles at this locus were defined by MspI restriction fragments of 3.0 kilobase pairs (M3.0) and 3.7 kilobase pairs (M3.7) respectively. The M3.7 allele was significantly more common (P<0.02) in Caucasian subjects who were normo-lipaemic (34%, 20/59) than in those who were hypertriglyceridaemic (16%, 16/98). Serum triglyceride levels were measured in 126 Caucasian subjects with different combinations of disease-associated alleles at the Apo AII and Apo CIII gene loci. Mean serum triglyceride levels were found to be significantly higher (P<0.05) in subjects with disease-associated alleles of both the Apo CIII and Apo AII genes, compared with subjects with a disease-associated allele of one or neither locus.     

The gender-specific apolipoprotein E genotype influence on the distribution of plasma lipids and apolipoproteins in the population of Rochester, Minnesota. II. Regression relationships with concomitants.

The influence of the apolipoprotein E (Apo E) polymorphism and gender on the regression relationships between each of nine plasma lipid and apolipoprotein traits (total cholesterol; ln triglycerides; high-density-lipoprotein cholesterol; apolipoproteins AI, AII, B, and CII; ln CIII; and ln E) and four concomitants (age, weight, waist-to-hip ratio, and smoking) was studied in 507 unrelated individuals representative of the adult population of Rochester, MN. Analyses are presented separately for females and males. Each lipid and apolipoprotein trait exhibited at least one Apo E genotype-specific regression relationship with the concomitants investigated in this study. In most cases the heterogeneity of regression was associated with differences between the epsilon 32 and epsilon 33 genotype. This study documents that the influence of Apo E genotype on average levels of plasma lipids and apolipoproteins varies among subdivisions of the population defined by age, body size, and smoking status.     

An apolipoprotein CIII marker associated with hypertriglyceridemia in Caucasians also confers increased risk in a west Japanese population

Polymorphisms and haplotypes at the adjacent apolipoprotein (apo) AI and CIII gene loci were investigated in 61 Japanese patients with triglycerides greater than 350 mg/dl and in 66 unrelated normolipidemic subjects. The polymorphic sites were the SstI site in the apoCIII 3 untranslated region, whose presence has previously been shown to be associated with hypertriglyceridemia (HTG) in Caucasians, and the MspI site in the third intron of the apoAI gene. The frequencies of the SstI minor allele (S2) were 0.48 in HTG patients and 0.25 in normolipidemic subjects (P < 0.00015). The frequencies of the MspI minor allele (M2) were 0.61 in HTG patients and 0.33 in normolipidemic subjects (P < 0.00001). The two polymorphic sites were in strong linkage disequilibrium, and maximum likelihood analysis supported the existence of three of the four possible haplotypes: S1-M1, S1-M2, and S2-M2. Since all S2 alleles were estimated to be present on M2-bearing chromosomes, the HTG-associated S2-M2 haplotype conferred the same approximate relative risk as the S2 allele alone when compared with the other two haplotypes (odds ratio 2.8). This study demonstrates that the S2 allele is a marker for HTG among west Japanese subjects as well as among Caucasians. The results suggest that S2-M2 chromosomes carry HTG susceptibility sequences that predate the separation of the Asian and Caucasian races.     

Diabetes-induced vascular dysfunction involves arginase I

Arginase can cause vascular dysfunction by competing with nitric oxide synthase for l-arginine and by increasing cell proliferation and collagen formation, which promote vascular fibrosis/stiffening. We have shown that increased arginase expression/activity contribute to vascular endothelial cell (EC) dysfunction. Here, we examined the roles of the two arginase isoforms, arginase I and II (AI and AII, respectively), in this process. Experiments were performed using streptozotocin-induced diabetic mice: wild-type (WT) mice and knockout mice lacking the AII isoform alone (AI(+/+)AII(-/-)) or in combination with partial deletion of AI (AI(+/-)AII (-/-)). EC-dependent vasorelaxation of aortic rings and arterial fibrosis and stiffness were assessed in relation to arginase activity and expression. Diabetes reduced mean EC-dependent vasorelaxation markedly in diabetic WT and AI(+/+)AII(-/-) aortas (53% and 44% vs. controls, respectively) compared with a 27% decrease in AI(+/-)AII (-/-) vessels. Coronary fibrosis was also increased in diabetic WT and AI(+/+)AII(-/-) mice (1.9- and 1.7-fold vs. controls, respectively) but was not altered in AI(+/-)AII (-/-) diabetic mice. Carotid stiffness was increased by 142% in WT diabetic mice compared with 51% in AI(+/+)AII(-/-) mice and 19% in AI(+/-)AII (-/-) mice. In diabetic WT and AI(+/+)AII(-/-) mice, aortic arginase activity and AI expression were significantly increased compared with control mice, but neither parameter was altered in AI(+/-)AII (-/-) mice. In summary, AI(+/-)AII (-/-) mice exhibit better EC-dependent vasodilation and less vascular stiffness and coronary fibrosis compared with diabetic WT and AI(+/+)AII(-/-) mice. These data indicate a major involvement of AI in diabetes-induced vascular dysfunction.     

Characterization of multi-cellulases of Sporotrichum cellulophilum by using monoclonal antibodies

Cellulases of Sporotrichum cellulophilum, CII1, CII2, CII3, CII5, CIII1, CIII2, and CIV1 were purified to homogeneity by column chromatographies and preparative electrophoresis. The specific activity of CII3 was the highest (100 units/mg), while the activities of CII5, CIII1, and CII2 were low (12–17 units/mg). The molecular weight of CII2 was 19,000, while those of the others ranged from 46,000–63,000. All the cellulases were glycoproteins except for CII2. Three monoclonal antibodies (Mab CII11, Mab CII12, and MabCII13) were prepared against CII1, and Mab CIV11 against CIV1. From the immunological reactivities, it was found that CII1, CIII2, and CIV1 had a common antigenic site recognized by Mab CII11, Mab CII12, and Mab CII13, while CII12 and CVI1 had a different antigenic site that was recognized by Mab CIV11, MabCII11, MabCII12, MabCII13, and MabCIV11 did not react with CII2, CII3, CII5, and CIII1. The classification of these cellulases was discussed.     

Protein transfer between A-I-containing lipoprotein subpopulations: evidence of non-transferable A-I in particles with A-II.

Transfer of apolipoproteins (apo) between the two subpopulations of apo A-I-containing lipoproteins in human plasma: those with A-II [Lp(AI w AII)] and those without [Lp(AI w/o AII)], were studied by observing the transfer of 125I-apo from a radiolabeled subpopulation to an unlabeled subpopulation in vitro. When Lp(AI w AII) was directly radioiodinated, 50.3 +/- 7.4 and 19.5 +/- 7.7% (n = 6) of the total radioactivity was associated with A-I and A-II, respectively. In radioiodinated Lp(AI w/o AII), 71.5 +/- 6.8% (n = 6) of the total radioactivity was A-I-associated. Time-course studies showed that, while some radiolabeled proteins transferred from one population of HDL particles to another within minutes, at least several hours were necessary for transfer to approach equilibrium. Incubation of the subpopulations at equal A-I mass resulted in the transfer of 51.8 +/- 5.0% (n = 4) of total radioactivity from [125I]Lp(AI w/o AII) to Lp(AI w AII) at 37 degrees C in 24 h. The specific activity (S.A.) of A-I in the two subpopulations after incubation was nearly identical. Under similar incubation conditions, only 13.4 +/- 4.6% (n = 4) of total radioactivity was transferred from [125I]Lp(AI w AII) to Lp(AI w/o AII). The S.A. of A-I after incubation was 2-fold higher in particles with A-II than in particles without A-II. These phenomena were also observed with iodinated high-density lipoproteins (HDL) isolated by ultracentrifugation and subsequently subfractionated by immunoaffinity chromatography. However, when Lp(AI w AII) radiolabeled by in vitro exchange with free [125I]A-I was incubated with unlabeled Lp(AI w/o AII), the S.A. of A-I in particles with and without A-II differed by only 18% after incubation. These data are consistent with the following: (1) in both populations of HDL particles, some radiolabeled proteins transferred rapidly (minutes or less), while others transferred slowly (hours); (2) when Lp(AI w AII) and Lp(AI w/o AII) were directly iodinated, all labeled A-I in particles without A-II were transferable, but some labeled AI in particles with A-II were not; (3) when Lp(AI w AII) were labeled by in vitro exchange with [125I]A-I, considerably more labeled A-I were transferable. These observations suggest the presence of non-transferable A-I in Lp(AI w AII).     

Studies of the lipid binding characteristics of the apolipoproteins from human high density lipoprotein. II. Calorimetry of the binding of apo AI and apo AII with phospholipids.

The interactions of lysophosphatidylcholine and synthetic 1,2-dimyristoyl-sn-glycerophosphocholine (DMPC) liposomes with the isolated HDL-apolipoproteins, apo AI and apo AII, has been studied by microcalorimetry. Complex formation is a highly exothermal process characterized by a maximal enthalpy of about --200 kcal/mol of apoprotein when added to DMPC at 28 degrees C in 0.05 M sodium carbonate/bicarbonate buffer, pH 9.6. For the apo AI apoprotein, the binding consists of two processes, one endothermal occurring at low phospholipid/protein ratios and one exothermal predominant at higher phospholipid levels. The endothermal process has been attributed to a lipid-induced disaggregation of the apo AI while the exothermal process is similar to the binding of apo AII or apo HDL to phospholipids. The binding of a constant AI and apo AII, demonstrates the existence of a maximal association at a 1 : 1 molar ratio of the apolipoproteins. The sequential binding of DMPC to apo AI and apo AII suggests the existence of cooperativity between the two apoproteins in phospholipid binding as apo AII promotes the incorporation of apo AI into a protein-phospholipid complex.     

Altered particle size distribution of apolipoprotein A-I-containing lipoproteins in subjects with coronary artery disease

Plasma high density lipoproteins (HDL) can be separated into two subpopulations of apolipoprotein A-I-containing particles: those that also contain apoA-II [Lp(AI w AII)] and those that do not [Lp(AI w/o AII)]. These particles were isolated by immunoaffinity chromatography from 17 men (9 normolipidemic (NL), 8 hyperlipidemic (HL) with symptomatic coronary artery disease (CAD), from 17 NL men without any symptoms of CAD (healthy controls), and from 10 NL men with entirely normal coronary arteriograms (CAD-free controls). The distributions of particle size in these two subpopulations were determined by gradient gel electrophoresis and densitometric scanning. Approximately half of the Lp(AI w AII) particles in all subjects were distributed in the 8.2-9.2 nm interval. For patients with CAD, a greater fraction of the particles were small, in the 7.0-8.2 nm interval [33% in CAD vs. 26% in CAD-free controls (P less than 0.01) and 19% in healthy controls (P less than 0.0001)], and a smaller fraction of the particles were in the 9.2-11.2 nm interval (14% in CAD vs. 24% in CAD-free control (P less than 0.002) and healthy control groups (P less than 0.001). The Lp(AI w/o AII) of both control groups were primarily composed of two discrete subpopulations in the 8.2-9.2 nm and the 9.2-11.2 nm intervals. In CAD patients there were fewer particles in the 9.2-11.2 nm size interval (23% in CAD vs. 33% in CAD-free controls (P less than 0.005) and 36% in healthy controls (P less than 0.0001), and more particles in the smallest 7.0-8.2 nm size interval (32% in CAD vs. 23% in CAD-free controls (P less than 0.01) and 18% in healthy controls (P less than 0.001]. Thus, the spectrum of HDL particle sizes in patients with CAD tends to be shifted toward the smaller particle when compared with the two control groups. This was observed in both NL and HL patients with HDL cholesterol (CH) values in the normal range. As a group, CAD patients had lower HDL (42 +/- 7 mg/dl) and HDL2 (6 +/- 4 mg/dl) CH than healthy (HDL: 49 +/- 7, HDL2: 12 +/- 6 mg/dl) and CAD-free (HDL: 51 +/- 9, HDL2: 12 +/- 6 mg/dl) controls. When controls and patients were compared for their frequencies of abnormal HDL CH levels and particle sizes, abnormalities in HDL and HDL2 CH levels were not significantly more frequent (twofold) among CAD patients than among controls.(ABSTRACT TRUNCATED AT 400 WORDS)     

Effects of conjugated equine estrogen and medroxyprogesterone acetate on lipoprotein(a) and other lipoproteins in japanese postmenopausal women with and without dyslipidemia

BACKGROUND/AIM: The cardiovascular effects of postmenopausal hormone replacement are controversially discussed. We investigated the effects of 12 months of treatment with conjugated equine estrogen and medroxyprogesterone acetate on lipoprotein(a) [Lp(a)] and other lipoproteins in Japanese postmenopausal women (PMW) with and without dyslipidemia. METHODS: Forty-three normolipidemic and 17 dyslipidemic PMW [total cholesterol (TC) >/=220 mg/dl or triglyceride (TG) >/=150 mg/dl] received conjugated equine estrogen (0.625 mg) plus medroxyprogesterone acetate (2.5 mg) daily for 12 months, and the results were compared with those of 26 normolipidemic and 14 dyslipidemic subjects declining this treatment as controls. The fasting serum levels of Lp(a), TC, TG, high-density lipoprotein cholesterol, low- density lipoprotein cholesterol, apolipoprotein (Apo) AI, Apo AII, Apo B, Apo CII, and Apo E were measured in each subject at baseline and 12 months after this treatment initiation. RESULTS: The treatment decreased Lp(a) similarly in normolipidemic and dyslipidemic PMW and decreased TC, low-density lipoprotein cholesterol, Apo CII, and Apo E and increased high-density lipoprotein cholesterol, Apo AI, and Apo AII in both groups. The therapy also significantly increased TG in normolipidemic but not dyslipidemic subjects. In controls, the levels of Lp(a) and other lipoproteins were unaltered. CONCLUSIONS: In PMW with or without dyslipidemia, improvement in Lp(a) and other lipoproteins may represent cardiovascular benefits of hormone replacement therapy. However, an elevation of the TG levels seen with the therapy warrants caution, especially in PMW without dyslipidemia.     

Development of a sensitive ELISA to quantify apolipoprotein CIII in nonhuman primate serum

Apolipoprotein CIII (apoCIII), a major constituent of triglyceride-rich lipoprotein, has been proposed as a key contributor to hypertriglyceridemia on the basis of its inhibitory effects on lipoprotein lipase. Many immunochemical methods have been developed for human apoCIII quantification, including ELISA. However, a sensitive and quantitative assay for nonhuman primates is not commercially available. We developed a sensitive, quantitative, and highly specific sandwich ELISA to measure apoCIII in both nonhuman primate and human serum. Our assay generates a linear calibration curve from 0.01 μg/ml to 10 μg/ml using an apoCIII standard that was purified from cynomolgus monkey serum. It is highly reproducible (intra- and interplate CV < 5% and < 8%, respectively), sensitive enough to distinguish 10% difference of apoCIII present in serum, and has no interference from purified human apolipoprotein AI, AII, B, CI, CII, or E. The same assay can also be used to measure human apoCIII with a linear calibration curve from 0.005 μg/ml to 1 μg/ml using purified human apoCIII as the standard. This fast and highly sensitive ELISA could be a useful tool to investigate the role of apoCIII in lipoprotein transport and cardiovascular disease.     

Apolipoproteins as the basis for heterogeneity in high-density lipoprotein2 and high-density lipoprotein3. Studies by isoelectric focusing on agarose films

A method is described for the isoelectric focusing (IEF) of lipoproteins on thin films of agarose. Within a pH gradient of 4.60-5.30 both high-density lipoproteins 2 and 3 (HDL2 and HDL3) are resolved into more than 10 fractions which could be stained either for protein or for lipids. The isoelectric focusing patterns for HDL2 and HDL3 are similar although HDL2 appears richer in the more alkaline bands. Narrow film strips from the IEF separation of HDL2 and HDL3 were interfaced with various agarose plates containing antisera against apolipoproteins apoAI, apoAII and apoCIII either alone or in combination, to provide two-dimensional IEF immunoelectrophoresis patterns. This technique demonstrated that apoAI and apoAII were present throughout the IEF gel for both subclasses of HDL. It also provided evidence for the existence of lipoproteins containing both apoAI and apoAII and other lipoproteins present in the alkaline region of the gel which contained apoAI but no apoAII. ApoCIII was found mostly in acidic lipoproteins and was not distributed identically in HDL2 and HDL3. The lipoproteins separated by IEF on agarose were also analysed by two-dimensional IEF-SDS electrophoresis and the individual apolipoproteins were identified by reaction with antibodies to apolipoproteins AI, AII, CI, CII, CIII, D, and E. This technique confirmed that in IEF of HDL, apoAI extended throughout the spectrum of lipoproteins whereas apoE was only present in alkaline lipoproteins and apoD was only present in acidic lipoproteins. IEF on agarose of either HDL2 or HDL3 allowed us to collect eight different fractions, which have the same pI in either lipoprotein class. The apolipoprotein composition of each isolated band was analysed by electroimmuno-assays for apolipoproteins AI, AII, CI, CII, CIII, D, and E and the results expressed as the ratio of the measured apolipoprotein to measured apoAI. In both HDL2 and HDL3, acidic lipoprotein fractions were enriched in apoAII, apoCIII and apoD. ApoCII and apoCII were not similarly distributed in HDL2 and HDL3 subfractions whereas the apoCI distribution was similar in both classes. Noteworthy in all experiments was the difference in the distributions of apoCI, apoCII, and apoCIII in HDL2 and HDL3, which indicated that the existence of a lipoprotein containing simultaneously CI, CII and CIII can only account for a small fraction of these apolipoproteins. Therefore these experiments substantiate the theory of the protein basis of HDL heterogeneity and suggest that the majority of apolipoproteins are present in complexes which upon IEF result in lipoprotein fractions of identical pI for both HDL2 or HDL3.(ABSTRACT TRUNCATED AT 400 WORDS)     

脂蛋白、载脂蛋白和脂蛋白受体与衰老

本文观察了新生儿(脐带血),青年(18—24岁),老年(55—65岁)各40例的血脂、脂蛋白、载脂蛋白和低密度脂蛋白LDL受体功能的变化。结果表明,新生儿的血脂,脂蛋白和载脂蛋白含量在各年龄组中最低(P<0.01),其LDL受体结合水平最高,(P<0.01)。血清TC,TG,LDL-C,apo B和CII随增龄上升,但LDL受体水平和HDL-C,apo AI,AII的增龄变化不明显。该结果指出,衰老对LDL受体的结合水平和HDL-C,apo AI,AII的影响似乎不大。另方面说明,TC,LDL-C和apo B浓度随增龄增加而不伴有相应的LDL受体结合水平及HDL-C,APO AI,AII浓度的上升,使老年期的脂蛋白代谢平衡被打破,因而促使高胆固醇血症和动脉粥样斑块的形成。     

Covalent binding of photosensitive 1-(12-azido-[9,10(-3)H2]oleoyl)glycero-3-phosphocholine (lysolecithin) to human serum high density apolipoproteins.

Human serum high density apoproteins were complexed with increasing concentrations of 1-(12-azido-[9,10(-3)H2]oleoyl)glycero-3-phosphocholine up to the saturation concentration (72 mol lysolecithin per mol apo HDL). Ultraviolet irradiation generated the nitrene which led to crosslinking with the two main apolipoproteins AI and AII. Methods are described for the removal of excess, unbound lipid and the column chromatographic separation of the lipopolypeptides AI and AII.     

The gender-specific apolipoprotein E genotype influence on the distribution of plasma lipids and apolipoproteins in the population of Rochester, MN. III. Correlations and covariances.

The gender-specific influence that the apolipoprotein E (ApoE) polymorphism has on the correlations and covariances between pairs of nine plasma lipid and apolipoprotein traits (total cholesterol; in triglycerides; high-density-lipoprotein cholesterol; apolipoproteins AI, AII, B, CII, lnCIII, and lnE) was studied in 507 unrelated individuals representative of the adult population of Rochester, MN. Analyses are presented separately for females and males. The Apo E polymorphism had a significant influence on a large number (10 of 36) of correlations and covariances in females and on a small number (3 of 36) in males. The contribution of allelic variation in the Apo E gene to the definition of multivariate measures of the 36-dimensional correlation structure was evaluated. The influence of Apo E genotype on correlation structure was gender dependent. These findings were used to demonstrate how heterogeneity of risk-factor correlations and covariances among genotype-gender subgroups of the population at large may influence the evaluation of risk of coronary artery disease.     

Isolation, characterization and comparative aspects of the major serum apolipoproteins, B-100 and AI, in the common marmoset, Callithrix jacchus

The two major apolipoproteins of marmoset serum have been isolated and characterized, and on the basis of physicochemical and immunological criteria are homologous with the human AI and B-100 proteins. Marmoset apolipoprotein AI was the principal protein of high-density lipoproteins (HDL) and was purified by gel filtration chromatography and electrophoresis in alkaline-urea polyacrylamide gel followed by electrophoretic elution. Purified marmoset apolipoprotein AI displayed an Mr of approx. 27000, was polymorphic (five forms) on isoelectric focussing, with pI values in the range 4.8-5.0, and migrated similarly to human apolipoprotein AI in alkaline-urea gels. An overall resemblance was seen in the amino acid composition of marmoset apolipoprotein AI and that of its human counterpart with the notable exception that marmoset AI contained 1 isoleucine residue/mole. An immunological reaction of partial identity between the human and monkey proteins was seen upon immunodiffusion of their HDLs against antiserum to human apolipoprotein AI. Marmoset B-100 was the predominant apoprotein of VLDL and LDL, resembling the human protein in its elution profile on gel filtration chromatography in anionic detergent, and in its high apparent Mr (approx. 520000). The marmoset and human B-100 proteins were alike in amino acid composition and carbohydrate content. Moreover, their immunological behaviour with an antiserum to marmoset apolipoprotein B showed them to share certain antigenic determinant(s). We conclude that the physicochemical properties of the principle apolipoproteins of Callithrix jacchus, a New World primate, markedly resemble those of the human AI and B-100 proteins, suggesting therefore that they may function similarly in lipid transport and metabolism. Counterparts to human apolipoproteins AII, E, CII and CIII have also been tentatively identified.