A i-antitrypsin

In inflammatory conditions, activated PMNs may pro-teolytically (by release of lysosomal enzymes) and oxidatively (by release of HOCl) inactivate ai-antitrypsin. Studies of synovial fluid samples from patients with RA showed that a i-antitrypsin was both cleaved and oxidized, resulting in inactivation (Chidwick et al., 1991, 1994). Free-radical attack on ai-antitrypsin and its subsequent inactivation may contribute to the destruction of joint tissues in arthritis due to the imbalance between elastase and its inhibitors. 

Failure/inelfective functioning of one or more of these mechanisms can impair normal respiratory function, e.g. emphysema is a condition in which the alveoli of the lungs are damaged, which compromises the lung s capacity to exchange gases, and breathlessness often results. This condition is often promoted by smoking, respiratory infections or a deficiency in the production of serum a i-antitrypsin. 

Obstructive lung disease is commonly associated with smoking or prolonged exposure to industrial smokes and fumes. The destruction of lung tissue in emphysema is permanent and irreversible and development ofthe condition is linked to deficiency of alpha-1-antitrypsin (a i-antitrypsin). 

In adults, a severe form of lung injury can develop in association with sepsis, pneumonia, and injury to the lungs due to trauma or surgery. This catastrophic disorder is known as acute respiratory distress syndrome (ARDS) and has a mortality rate of more than 40%. In ARDS, one of the major problems is a massive influx of activated neurophils which damage both vascular endothelium and alveolar epithelium and result in massive pulmonary edema and impairment of surfactant function. Neutrophil proteinases (e.g., elastase) break down surfactant proteins. A potential therapeutic strategy in ARDS involves administration of both surfactant and antiproteinases (e.g., recombinant a I -antitrypsin). 

Schematic representation of the amino acid sequence of a i -antitrypsin (PiMM) and some of its variants. The amino acid residues shown are not drawn to scale CHO represents the oligosaccharide units.

Without sample preparation, the analysis of a dilute serum sample by CE with ultraviolet (UV) detection leads to the separation and detection of the major serum proteins, y-globulin, transferrin (Tf), P-lipoproteins, haptoglobin, a2-macroglobulin, a i-antitrypsin (AAT), a i-lipoproteins, hiunan semm albumin (HSA), pre-albumin, and complements [32], as shown in Figure 22.4. These proteins often mask other important analytes that are usually more clinically relevant than the major proteins. In fact, it has been widely mentioned that global approaches to proteome analysis detect less than 0.1% of the protein species present in a sample, which span a range of 10 orders of magnitude between the most abundant and the less abundant proteins [33]. 

Determination of acute-phase proteins (CRP, orosomucoid, haptoglobin, transferrin, prealbumin), immunoglobulins (IgA, IgG, IgM), compressive markers (albumin, fibrinogen), markers of tissue destruction (Apo A-I, A-II, Apo B), components of complement (C3, C4), proteinase inhibitors (antithrombin HI, a -antitrypsin). The measurement was performed simultaneously in CSF and in serum (plasma) by a laser nephelometric method. The functional state of the blood-CSF barrier was evaluated numerically with the help of the quotient Q = Albcsp/s and also by the intrathecal synthesis of immunoglobulins according to Reiber s formula and for each class—IgG, IgM, IgA. 

Song, S., M. Scott-Jorgensen, I Wang, A. Poirier, I Crawford, M. Campbell-Thompson, and T. Flotte, Intramuscular administration of recombinant adeno-associated virus 2 alpha-I antitrypsin (rAAV-SERPINAl) vectors in a nonhuman primate model safety and immunologic aspects. Mol Ther, 2002. 6(3) 329. 

Fig. 4.5.5 IEF pattern of a-1-antitrypsin. Sera from a control (lane 1), three CDG-I patients (CDG-Ia, CDG-Ic and CDG-Id lanes 2-4) and three CDG-II patients (CDG- , CDG-IId and CDG-IIx lanes 5-7) were analysed by IEF. The normal pattern (lane 1, left) reveals seven bands. In abnormal patterns (lanes 2-7, left to right), the position of the first additional abnormal cathodal band is indicated by an arrow. This band and also all bands below are abnormal and indicate a glycosylation deficiency...

Gerbod-Giannone, M.C., A. Del Castillo-Olivares, S. Janciauskiene, G. Gil, and P.B. Hylemon (2002). Suppression of cholesterol 7a-hydroxylase transcription and bile acid synthesis by an Oj-antitrypsin peptide via interaction with a I-fetoprotein transcription factor. J. Biol. Chem. Ill, 42973 2980. 

FIGURE 22.4 Electropherogram of a diluted normal control serum. Peaks 1, neutral marker 2, y-globulin 3, transferrin 4, P-lipoproteins 5, haptoglobin 6, a2-macroglobulin 7, a j-antitrypsin 8, aj-lipoproteins 9, albumin 10, prealbumin 2, complements. Analytical conditions fused-silica capillary 25 cm x 25 xm i.d. buffer Beckman proprietary buffer of pH 10.0 10 kV 22 C. (From Chen, E-T.A., J. Chromatogr., 559, 445, 1991. With permission.)... 

It appears that, generally, sialic acid is not a part of an antigenic determinant (atropinesterase and orosomucoid) nor a functioning part of a catalytic or binding site ( i-antitrypsin, atropinesterase, cemloplasmin, and serum cholinesterase). However, sialic acid does seem to play a role in transport ( i-antitrypsin). This effect is discussed more fully later in this chapter. Johnson et al. (1970) found that removal of sialic acid residues from the copper-containing protein cemloplasmin had no effect on its kinetic properties as an oxidase. They concluded that the terminal sialic acid residues do not influence the stmcture and function of the active sites in cemloplasmin. 

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