George E. Chapman's research while affiliated with Garvan Institute of Medical Research and other places

Publications (16)

Article
Capillary electrophoresis and laser-induced fluorescence detection have been used to fingerprint the 2-aminoacridone derivatives of complex glycans released from bovine fetuin and human IgG monoclonal antibodies. The utility of this method in distinguishing between N- and O-linked oligosaccharides and in determining the presence of sialic acid resi...
Article
Excessive endogenous production or exogenous administration of human growth hormone (hGH) causes insulin resistance at both the hepatic and extrahepatic levels. However, which extrahepatic tissues are involved have not been defined. We have examined the diabetogenic action of authentic biosynthetic hGH on whole body glucose disposal, hepatic glucos...
Article
Osteocalcin the major gamma carboxyglutamic acid containing protein of vertebrate bone has been purified from the bones of a specimen of Pachyornis elephantopus, a species of the extinct class of New Zealand ratite birds, the moas. The sequence of the N-terminal region of moa osteocalcin was determined using gas phase N-terminal sequencing. The N-t...
Chapter
Systems for multi-stage chromatographic purification of biotechnologysourced therapeutic proteins have been designed and built using carmercially available components, modified where necessary. The systems operate as sterile self-contained units totally under computer control. The chemistries of the individual stages are integrated so that the prod...
Article
We have used mammalian cell lines, constructed with the expression system described, to express high levels of a heterologous gene product (human growth hormone) without recourse to gene amplification. The system employs commonly available components that combine efficiently to yield high expression. These components include the human metallothione...
Article
The distribution of 125I radioactivity in the liver, kidneys, adrenals and serum of male rats was measured 10 minutes after an intravenous bolus of 125I-labelled human growth hormone (hGH) was administered in the presence or absence of a large excess of ovine growth hormone or ovine prolactin. The hGH binding sites in the adrenals had displacement...
Article
A technique is described to study the effect of acetylation of individual lysine residues in peptide hormones on the affinity for their receptors, and is illustrated for the case of human growth hormone (hGH) binding to somatogenic receptors. The hGH was partially acetylated with high specific activity [3H]-acetic anhydride and the product ([3H]-Ac...
Article
Osteocalcin (OC), the major gamma carboxyglutamic acid (Gla)-containing protein of vertebrate bone, has been isolated from bones of the emu (Dromaius novaehollandae) and the primary structure determined by a combination of gas phase N-terminal sequencing of the intact molecule and a proteolytic fragment, and carboxypeptidase Y C-terminal sequencing...
Article
Full-text available
The oxidation of the methionine residues of human growth hormone (hGH) and human chorionic somatomammotropin (hCS) to methionine sulfoxide by hydrogen peroxide has been studied. The kinetics of oxidation of individual methionine residues has been measured by reverse-phase high pressure liquid chromatography tryptic peptide mapping. Met-170 is compl...
Article
Serum osteocalcin (OC) levels were measured in 19 asthmatic patients receiving long term glucocorticoid therapy and in age- and sex-matched asthmatic patients not receiving this treatment. In the glucocorticoid-treated patients, the mean OC level was approximately 50% less than that in the control group (P less than 0.001), and there was a direct c...
Article
Osteocalcin (the 6,000 dalton Mr gamma-carboxyglutamate-containing protein of bone) has been detected in acid extracts of bones of the extinct class of New Zealand ratite birds, the moas, using a radioimmunoassay for sheep osteocalcin. The immunoreactive osteocalcin of the extracts of two of these bones (the fibulae from two specimens of Pachyornis...
Article
The amino acid sequences of osteocalcins from cortical long bones of goat, pig and wallaby have been determined by manual microsequencing methods. The location of the gamma-carboxyglutamic acid residues were identified by N-terminal degradation of peptides in which these residues had been tritium-labelled in the gamma-H position and subsequently th...
Article
Reversed-phase high performance liquid chromatography (RP-HPLC) has been used to separate the peptides generated by tryptic cleavage of human growth hormone (hGH) and the 20K dalton human growth hormone variant. The total amino acid compositions of both these pituitary proteins has been accounted for on the basis of these chromatographic mapping pr...
Article
An integrated scheme for the extraction and purification of human pituitary hormones from frozen glands has been developed. The method yields 6.3 mg/gland of monomeric pyrogen-free GH in a single fraction, with a potency of 2.5-3.1 IU/mg, as estimated by bioassay, radioreceptor assay, and RIA, with a further 0.6 mg/gland recovered from side fractio...

Citations

... Laboratory Animals (2008) 42 BAP EIA test has been used for sheep , Chavassieux et al. 2001, Liesegang et al. 2003 and the cross-reactivity of ovine OC with human OC is reported as 83% (Mende et al. 1984). ...
... Second, since the 20-kDa hGH is a hGH that lacks amino acid residues 32-46, a tryptic digest of 20-kDa hGH would produce a tryptic peptide 4 corresponding to amino acid residues 20-31 + 47-64 of 22kDa hGH comprising the sequence (LHQLAFDTYQEFNPQTSLCFSESIPTPSNR) with a monoisotopic mass of 3526.65 (when reduced and alkylated with acetamide). This peptide has been reported as a peptide generated by tryptic cleavage of 20-kDa hGH ( Hearn et al. 1983). In our experiments, the tryptic peptides of MER-45-kDa hGH contained a peptide with a mass identical to tryptic peptide 4 of 22kDa hGH (residues 20-38; Table 2) but the mass spectra did not display a mass corresponding to a tryptic peptide 4 of 20-kDa hGH. ...
... This system has been used successfully for the overexpression of a number of foreign genes, including a tissue inhibitor of metalloproteinase (Cockett et al. 1990). On the other hand, another approach to increasing cellular productivity is to improve the efficiency of transcription for each gene copy by utilizing potent promoters (Wang et al. 1984;Takebe et al. 1988; Le et al. 1988) or inducible promoters (Friedman et al. 1989). ...
... Sequencing. The first successful recovery of an ancient protein sequence was made by Lila Huq 65 using Edman degradation sequencing of osteocalcin from the bone of a moa (Pachyornis elephantopus), an extinct flightless bird. This achievement was particularly remarkable, as one of the authors of this review (M.C.) will testify, because this technology is extremely ill suited to ancient proteins. ...
Reference: Paleoproteomics
... T h e o ve r t h e p a s t d e c a d e s , G H administration has been accepted as anti-ageing, physical growth, and bone health treatments in medical clinics, and the physiological effects of GH are well presented in the literature (Doga et al. 2006;Henwood et al. 2002;Woodhouse et al. 2006). Notably, injection of GH is also suggested to antagonize the effects of insulin on glucose and lipid metabolism; Cartee et al. 1995;Chrisoulidou et al. 2000; Groop et al. 2005;Ng et al. 1990) in vivo experimental investigations demonstrate that GH treatment can reduce glucose and insulin and responses in animals (Cartee & Bohn. 1995;Hou et al. 2003;Ng et al. 1990). ...
... Different concentrations of unlabeled caprine and human GH (0, 0.1, 1, 10, 100 and 1000 μg) were used in the assay and results showed that 1000 μg concentration of both unlabeled hormones disrupted the binding of the 125 I-rcGH at a maximum level. These results were in consensus with that of Tech et al. (1988). The cross reactive results explained that human GH binds with high affinity to the Bovidae microsomal membrane or with non-primates GHR and similar results have also been reported by Souza et al. (1995). ...
... It is understood that glucocorticoids affect the function of multiple cell types, with the strongest evidence indicating osteoblasts as the main target [49]. The transcription of osteocalcin, an osteoblast-specific gene, is suppressed by glucocorticoids [50] and serum levels of osteocalcin are reduced in patients receiving glucocorticoids [51,52]. Our study supports these findings, as we observed a significant negative correlation between serum cortisol and cortisone and OC in our patients on HC replacement therapy. ...
... However, a recent study suggests that preservation of this protein may not be exceptional (Burky et al., 1998) Even though the 35 carboxy-terminal residues of OC are highly conserved and the -carboxyglutamic acid (Gla) positions are invariant, the 13 amino-terminal residues of different species are highly variable allowing it to be used as a substrate for taxonomic studies (Hauschka et al., 1989; Huq et al., 1990). In addition, OC occurs exclusively in vertebrate mineralized tissues (Hauschka, 1980a); OC is absent in common fossil contaminators including microbes, invertebrates and plants (Hauschka, 1977; King, 1980; Muyzer et al., 1992 ); OC retains immunological specificity via radioimmunoassay (RIA) (Gundberg et al., 1984) and there is an extensive database of protein (Price et al., 1976; Poser et al., 1980; Price, 1983; Huq et al., 1984; Huq et al., 1987) and DNA sequences (Pan and Price, 1985; Celeste et al., 1986; Yoon et al., 1988; Lian et al., 1989) for OC. The objective of our current research is to develop new mass spectrometric techniques for sequencing ancient proteins. ...
... The oxidation of methionine to the methionine sulfoxide form has been widely reported for many types of proteins [12][13][14][15]. Although methionine oxidation has been reported to be reversible in vivo through the activity of the methionine sulfoxide reductase (MsR), which catalyzes the thioredoxin-dependent reduction of MetO back to Met, it is not yet clear whether, in the context of therapeutic mAbs, an oxidized methionine can be readily reduced back to Met [11,[16][17][18]. ...
... [1,3,[10][11][12][13] Additionally, because of its close association with hydroxyapatite, size, and acidity, it has been hypothesized to persist into the deep time making it a prime target for paleontological and archaeological investigations. [14][15][16][17][18][19][20][21][22][23][24][25] It has also been a target for fossil remains because the N-terminal residues are variable providing greater phylogenetically informative sequences than other commonly preserved proteins in bone (e.g., collagen I). [18] It is a small protein (~5800 Da) with three vitamin K dependent γ-carboxylated glutamic acid residues (Gla) at positions 17, 21, and 24 [26] that allow for direct binding to calcium in hydroxyapatite. ...