High-density lipoprotein (HDL) is the most abundant lipoprotein particle in the plasma and a negative risk factor of atherosclerosis. By using a proteomic approach it is possible to obtain detailed information about its protein content and protein modifications that may give new information about the physiological roles of HDL. In this study the two subfractions; HDL(2) and HDL(3), were isolated by two-step discontinuous density-gradient ultracentrifugation and the proteins were separated with two-dimensional gel electrophoresis and identified with peptide mass fingerprinting, using matrix-assisted laser desorption/ionisation time of flight mass spectrometry. Identified proteins in HDL were: the dominating apo A-I as six isoforms, four of them with a glycosylation pattern and one of them with retained propeptide, apolipoprotein (apo) A-II, apo A-IV, apo C-I, apo C-II, apo C-III (two isoforms), apo E (five isoforms), the recently discovered apo M (two isoforms), serum amyloid A (two isoforms) and serum amyloid A-IV (six isoforms). Furthermore, alpha-1-antitrypsin was identified in HDL for the first time. Additionally, salivary alpha-amylase was identified as two isoforms in HDL(2), and apo L and a glycosylated apo A-II were identified in HDL(3). Besides confirming the presence of different apolipoproteins, this study indicates new patterns of glycosylated apo A-I and apo A-II. Furthermore, the study reveals new proteins in HDL; alpha-1-antitrypsin and salivary alpha-amylase. Further investigations about these proteins may give new insight into the functional role of HDL in coronary artery diseases.
The molecular mechanisms underlying the relationship between low-density lipoprotein (LDL) and the risk of atherosclerosis are not clear. Therefore, detailed information about the protein composition of LDL may contribute to reveal its role in atherogenesis and the mechanisms that lead to coronary disease in humans. Here, we sought to map the proteins in human LDL by a proteomic approach. LDL was isolated by two-step discontinuous density-gradient ultracentrifugation and the proteins were separated with two-dimensional gel electrophoresis and identified with peptide mass fingerprinting, using matrix assisted laser desorption/ionization-time of flight-mass spectrometry and with amino acid sequencing using electrospray ionization tandem mass spectrometry. These procedures identified apo B-100, apo C-II, apo C-III (three isoforms), apo E (four isoforms), apo A-I (two isoforms), apo A-IV, apo J and apo M (three isoforms not previously described). In addition, three proteins that have not previously been identified in LDL were found: serum amyloid A-IV (two isoforms), calgranulin A, and lysozyme C. The identities of apo M, calgranulin A, and lysozyme C were confirmed by sequence information obtained after collision-induced dissociation fragmentation of peptides characteristic for these proteins. Moreover, the presence of lysozyme C was further corroborated by demonstrating enriched hydrolytic activity in LDL against Micrococcus lysodeikticus. These results indicate that in addition to the dominating apo B-100, LDL contains a number of other apolipoproteins, many of which occur in different isoforms. The demonstration, for the first time, that LDL contains calgranulin A and lysozyme C raises the possibility that LDL proteins may play hitherto unknown role(s) in immune and inflammatory reactions of the arterial wall.
This paper quantifies environmental and economic benefits of the Integrated Product Service Offering (IPSO) in real practice from a life cycle perspective, in comparison with its corresponding product-sales type business as a reference. The paper also discusses the engineering activities contributing to those effects, as well as their enablers. To reach this goal, the paper investigates three IPSOs as real-life business cases in industry. Those cases are selected from different sectors and have different characteristics. In addition, the paper calculates and compares environmental impacts and economic costs of different offerings in each case through the use of Life Cycle Assessment and Life Cycle Costing, respectively. In all three cases, IPSOs had environmental and economic advantages in comparison with the product-sales type business. The engineering activities contributing to those advantages under IPSOs were recycling, remanufacturing, reuse, maintenance, and holistic planning and operation. The enablers were found to be high flexibility for realizing products and services and close relationships with relevant actors
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