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1.
Orthopedics ; 45(2): 97-102, 2022.
Article in English | MEDLINE | ID: mdl-34978514

ABSTRACT

Few studies have investigated nationwide patient trends and health care costs for reverse shoulder arthroplasty (RSA) after 2014. This study uses a large validated nationwide database to retrospectively assess changes in patient and hospital demographic features, hospital costs, and hospital charges for inpatient RSA procedures before and after implementation of the Affordable Care Act. The National Inpatient Sample database was used to identify all patients who underwent RSA between January 2011 and December 2015, yielding 163,171 patients (63.4% female; mean age, 72 years). Categorical data were assessed with chi-square/Fisher's exact test, and continuous data were assessed with analysis of variance. There was an increased proportion of RSA recipients identifying as Hispanic (4.1% to 4.8%) and Native American (0.1% to 0.4%; P<.0001). The proportion of patients who had Medicaid (1.4% to 2.4%) and private insurance (15.1% to 16.6%) increased as well (P<.0001). A decrease in mean hospital costs occurred between 2011 and 2015 (-$256; P=.002), whereas an increase occurred in hospital charges (+$6,314; P<.001). These findings provide insight on RSA use and patient demographic trends in the United States. Additionally, these results help to capture the effects of extended health coverage and new reimbursement models on hospital costs and charges. [Orthopedics. 2022;45(2):97-102.].


Subject(s)
Arthroplasty, Replacement, Shoulder , Patient Protection and Affordable Care Act , Aged , Female , Hospital Charges , Humans , Male , Medicaid , Retrospective Studies , United States
2.
J Mol Evol ; 63(5): 591-601, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17009125

ABSTRACT

The GH gene cluster in marmoset, Callithrix jacchus, comprises eight GH-like genes and pseudogenes and appears to have arisen as a consequence of gene duplications occurring independently of those leading to the human GH gene cluster. We report here the complete sequence of the marmoset GH gene locus, including the intergenic regions and 5' and 3' flanking sequence, and a study of the multiple GH-like genes of an additional New World monkey (NWM), the white-fronted capuchin, Cebus albifrons. The marmoset sequence includes 945 nucleotides (nt) of 5' flanking sequence and 1596 nt of 3' flanking sequence that are "unique"; between these are eight repeat units, including the eight GH genes/pseudogenes. The breakpoints between these repeats are very similar, indicating a regular pattern of gene duplication. These breakpoints do not correspond to those found in the much less regular human GH gene cluster. This and phylogenetic analysis of the repeat units within the marmoset gene cluster strongly support the independent origin of these gene clusters, and the idea that the episode of rapid evolution that occurred during GH evolution in primates preceded the gene duplications. The marmoset GH gene cluster also differs from that of human in having fewer and more evenly distributed Alu sequences (a single pair in each repeat unit) and a "P-element" upstream of every gene/pseudogene. In human there is no P-element upstream of the gene encoding pituitary GH, and these elements have been implicated in placental expression of the other genes of the cluster. The GH gene clusters in marmoset and capuchin appear to have arisen as the consequence of a single-gene duplication event, but in capuchin there was then a remarkable expansion of the GH locus, giving at least 40 GH-like genes and pseudogenes. Thus even among NWMs the GH gene cluster is very variable.


Subject(s)
Callithrix/genetics , Cebus/genetics , Evolution, Molecular , Growth Hormone/genetics , Primates/genetics , Alu Elements , Animals , Gene Conversion , Gene Duplication , Humans , Models, Genetic , Molecular Sequence Data , Multigene Family , Phylogeny , Sequence Analysis, DNA
3.
Gen Comp Endocrinol ; 146(2): 180-5, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16356499

ABSTRACT

In mammals, pituitary growth hormone (GH) is usually encoded by a single gene, but in some caprine ruminants there are two GH genes, and higher primates have a cluster of at least 5 GH-like genes. We have previously shown that in several artiodactyls (chevrotain, giraffe, and hippopotamus) there are two GH gene sequences, differing by 5-21 nucleotides (nt), but whether these arise from two distinct gene loci is unclear. We report here that in the red deer (Cervus elaphus) also there are two main GH gene sequences (designated A and B) differing at about 23 nt. Investigation of DNA from a number of individual animals demonstrated that this variation was due to allelic polymorphism, with individuals carrying either the A-type or the B-type sequence, or both. A- and B-type sequences showed some variation between individuals. The overall difference between the A and B sequences is substantial-greater than that between the GH gene sequences of three distinct bovine species, Bos taurus (ox), Bos indicus (zebu) and Bos grunniens (yak). The biological significance of the presence of two markedly differing GH gene sequences in red deer is not clear, but it is notable that several of the differences between the A and B sequences occur in the 5' upstream region, which may be associated with differences in gene expression.


Subject(s)
Deer/genetics , Growth Hormone/genetics , Polymorphism, Genetic , Animals , Base Sequence , Gene Expression Profiling , Molecular Sequence Data , Polymerase Chain Reaction , Sequence Analysis, DNA
4.
Gen Comp Endocrinol ; 143(1): 92-7, 2005 Aug.
Article in English | MEDLINE | ID: mdl-15993109

ABSTRACT

In mammals growth hormone (GH) is generally a strongly conserved protein, reflecting a slow rate of molecular evolution. However, during primate and artiodactyl evolution episodes of rapid change occurred, so that the GHs of higher primates and ruminants differ markedly from those of other mammals. To extend knowledge of GH evolution in Cetartiodactyla (Artiodactyla plus Cetacea) we have previously characterized GH genes from several members of this group, including the common dolphin. Surprisingly the sequence deduced for dolphin GH differed at several residues from that described previously for another cetacean, finback whale. To investigate this anomaly we have now cloned and characterized the GH gene from finback whale. The overall organization of this gene is similar to that of dolphin, and the deduced amino acid sequence of finback whale GH differs from that of dolphin GH at only residue 47, and from that of pig GH at only residue 149. Phylogenetic analysis of the data provides further support for inclusion of Cetacea within the order Cetartiodactyla, as sister group of Hippopotamidae. The results support the idea that in Cetartiodactyla a burst of rapid evolution of GH occurred after the separation of the line leading to ruminants from other cetartiodactyls. Overall, the GH gene in cetaceans appears to be evolving more slowly than in most other cetartiodactyls.


Subject(s)
Growth Hormone/genetics , Growth Hormone/metabolism , Whales/genetics , Amino Acid Sequence , Animals , Base Sequence , Cloning, Molecular , Molecular Sequence Data , Phylogeny , Polymerase Chain Reaction , Sequence Analysis, DNA
5.
J Mol Evol ; 60(5): 606-14, 2005 May.
Article in English | MEDLINE | ID: mdl-15983870

ABSTRACT

Pituitary prolactin, like growth hormone (GH) and several other protein hormones, shows an episodic pattern of molecular evolution in which sustained bursts of rapid change contrast with long periods of slow evolution. A period of rapid change occurred in the evolution of prolactin in primates, leading to marked sequence differences between human prolactin and that of nonprimate mammals. We have defined this burst more precisely by sequencing the coding regions of prolactin genes for a prosimian, the slow loris (Nycticebus pygmaeus), and a New World monkey, the marmoset (Callithrix jacchus). Slow loris prolactin is very similar in sequence to pig prolactin, so the episode of rapid change occurred during primate evolution, after the separation of lines leading to prosimians and higher primates. Marmoset prolactin is similar in sequence to human prolactin, so the accelerated evolution occurred before divergence of New World monkeys and Old World monkeys/apes. The burst of change was confined largely to coding sequence (nonsynonymous sites) for mature prolactin and is not marked in other components of the gene sequence. This and the observations that (1) there was no apparent loss of function during the episode of rapid evolution, (2) the rate of evolution slowed toward the basal rate after this burst, and (3) the distribution of substitutions in the prolactin molecule is very uneven support the idea that this episode of rapid change was due to positive adaptive selection. In the slow loris and marmoset there is no evidence for duplication of the prolactin gene, and evidence from another New World monkey (Cebus albifrons) and from the chimpanzee and human genome sequences, suggests that this is the general position in primates, contrasting with the situation for GH genes. The chimpanzee prolactin sequence differs from that of human at two residues and comparison of human and chimpanzee prolactin gene sequences suggests that noncoding regions associated with regulating expression may be evolving differently from other noncoding regions.


Subject(s)
Evolution, Molecular , Phylogeny , Primates/genetics , Prolactin/genetics , Amino Acid Sequence , Animals , Base Composition , Base Sequence , Cloning, Molecular , Cluster Analysis , Gene Components , Humans , Molecular Sequence Data , Sequence Alignment , Sequence Analysis, DNA
6.
J Mol Evol ; 58(6): 743-53, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15461431

ABSTRACT

The sequence of growth hormone (GH) is generally strongly conserved in mammals, but episodes of rapid change occurred during the evolution of primates and artiodactyls, when the rate of GH evolution apparently increased substantially. As a result the sequences of higher primate and ruminant GHs differ markedly from sequences of other mammalian GHs. In order to increase knowledge of GH evolution in Cetartiodactyla (Artiodactyla plus Cetacea) we have cloned and characterized GH genes from camel (Camelus dromedarius), hippopotamus (Hippopotamus amphibius), and giraffe (Giraffa camelopardalis), using genomic DNA and a polymerase chain reaction technique. As in other mammals, these GH genes comprise five exons and four introns. Two very similar GH gene sequences (encoding identical proteins) were found in each of hippopotamus and giraffe. The deduced sequence for the mature hippopotamus GH is identical to that of dolphin, in accord with current ideas of a close relationship between Cetacea and Hippopotamidae. The sequence of camel GH is identical to that reported previously for alpaca GH. The sequence of giraffe GH is very similar to that of other ruminants but differs from that of nonruminant cetartiodactyls at about 18 residues. The results demonstrate that the apparent burst of rapid evolution of GH occurred largely after the separation of the line leading to ruminants from other cetartiodactyls.


Subject(s)
Artiodactyla/genetics , Cetacea/genetics , Evolution, Molecular , Growth Hormone/genetics , Phylogeny , Amino Acid Sequence , Animals , Base Composition , Base Sequence , Cluster Analysis , DNA Primers , Gene Components , Molecular Sequence Data , Sequence Alignment , Sequence Analysis, DNA
7.
Gen Comp Endocrinol ; 127(3): 300-6, 2002 Jul.
Article in English | MEDLINE | ID: mdl-12225773

ABSTRACT

The sequence of growth hormone (GH) is generally strongly conserved in mammals, but episodes of rapid change occurred during the evolution of primates and artiodactyls, when the rate of GH evolution apparently increased at least 50-fold. As a result, the sequences of human and ruminant GHs differ substantially from those of other non-primate GHs. Recent molecular studies have suggested that cetaceans are closely related to artiodactyls and may be deeply nested within the artiodactyl phylogenetic tree. To extend the knowledge of GH in Cetartiodactyla (Artiodactyla plus Cetacea), we have cloned and characterised a single GH gene from the common dolphin (Delphinus delphis), using genomic DNA and a polymerase chain reaction technique. As in other mammals, the dolphin GH gene comprises five exons and four introns. The deduced sequence for the mature dolphin GH differs from that of pig at two residues only, showing that the apparent burst of rapid evolution of GH occurred largely after the separation of cetaceans and ruminants.


Subject(s)
Cloning, Molecular , Dolphins/genetics , Growth Hormone/genetics , Amino Acid Sequence , Animals , Artiodactyla/genetics , Base Sequence , DNA/genetics , Evolution, Molecular , Growth Hormone/chemistry , Humans , Molecular Sequence Data , Polymerase Chain Reaction , Sequence Alignment , Sequence Analysis, DNA
8.
J Mol Endocrinol ; 29(1): 89-97, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12200231

ABSTRACT

In most mammals pituitary GH is encoded by a single gene with no close relatives. However, in man the GH gene has been shown to be one of a cluster of five closely related genes, four of which are expressed in the placenta. Rhesus monkey also expresses at least five closely related GH-like genes, although the genomic organisation of these has not been fully reported. Here we describe the cloning and characterisation of GH-like genes in a new-world monkey, the marmoset (Callithrix jacchus). This species possesses a cluster of eight GH-like 'genes'. The gene at the 5' end of this cluster encodes pituitary GH and is similar to that encoding human GH. Five of the eight marmoset 'genes' are probably pseudogenes, since they include mutations which would prevent normal expression, including stop codons and small insertions/deletions that would change the reading frame. In one case a large part of a gene is deleted, and in another a large insertion is introduced into an exon. The remaining two marmoset genes are potentially expressible, as proteins with sequences substantially different (at 25-30% of all residues) from that of marmoset GH itself; whether and in which tissue(s) such expression actually occurs is not yet known. None of the marmoset genes is clearly equivalent to any of the human GH-like genes expressed in the placenta, and this and phylogenetic analysis suggest that the duplications that gave rise to the marmoset GH gene cluster occurred independently of those that gave rise to the corresponding cluster in man. Although it includes more 'genes', the marmoset cluster extends over a shorter region of chromosomal DNA (about 35 kb) than does the human GH gene cluster (about 50 kb).


Subject(s)
Growth Hormone/genetics , Multigene Family , Amino Acid Sequence , Animals , Base Sequence , Callithrix , Cloning, Molecular , DNA Primers , Evolution, Molecular , Gene Amplification , Growth Hormone/chemistry , Humans , Molecular Sequence Data , Phylogeny , Regulatory Sequences, Nucleic Acid , Sequence Homology, Amino Acid , Sequence Homology, Nucleic Acid
9.
Gen Comp Endocrinol ; 123(1): 62-72, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11551118

ABSTRACT

In mammals the sequence of pituitary growth hormone (GH) is generally strongly conserved, indicating a slow basal rate of molecular evolution. However, on two occasions, during the evolution of primates and that of cetartiodactyls, the rate of evolution has increased dramatically (25 to 50-fold) so that the sequences of human and ruminant GHs differ markedly from those of other mammalian GHs. To define further the burst of GH evolution that occurred in cetartiodactyls, the GH gene of the chevrotain (Tragulus javanicus) has been cloned and characterized by use of genomic DNA and a polymerase chain reaction technique. Two very similar gene sequences, which probably reflect allelic variation, were isolated. The deduced sequence for the mature chevrotain GH differs from that of the bovine or red deer GH at only two to three residues, and phylogenetic analysis shows that the burst of rapid evolution of GH that occurred in the Cetartiodactyla must have been completed before the divergence of the Tragulidae and the advanced ruminants (Pecora). The rate of evolution during this burst must therefore have been greater than previously estimated. In other aspects (including signal sequence, 5' upstream sequence, and synonymous substitutions in the coding sequence), the chevrotain GH gene differs considerably from the GH genes of other ruminants and here there is no evidence for the period of accelerated evolution that is seen for GH itself.


Subject(s)
Cloning, Molecular , Evolution, Molecular , Growth Hormone/genetics , Ruminants/genetics , Amino Acid Sequence , Animals , Base Sequence , Molecular Sequence Data , Polymerase Chain Reaction , Sequence Alignment
10.
J Mol Endocrinol ; 26(3): 249-58, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11357061

ABSTRACT

Pituitary growth hormone (GH), like several other protein hormones, shows an unusual episodic pattern of molecular evolution in which sustained bursts of rapid change are imposed on long periods of very slow evolution (near-stasis). A marked period of rapid change occurred in the evolution of GH in primates or a primate ancestor, and gave rise to the species specificity that is characteristic of human GH. We have defined more precisely the position of this burst by cloning and sequencing the GH genes for a prosimian, the slow loris (Nycticebus pygmaeus) and a New World monkey, marmoset (Callithrix jacchus). Slow loris GH is very similar in sequence to pig GH, demonstrating that the period of rapid change occurred during primate evolution, after the separation of lines leading to prosimians and higher primates. The putative marmoset GH is similar in sequence to human GH, demonstrating that the accelerated evolution occurred before divergence of New World monkeys and Old World monkeys/apes. The burst of change was confined largely to coding sequence for mature GH, and is not marked in other components of the gene sequence including signal peptide, 5' upstream region and introns. A number of factors support the idea that this episode of rapid change was due to positive adaptive selection. Thus (1) there is no apparent loss of function of GH in man compared with non-primates, (2) after the episode of rapid change the rate of evolution fell towards the slow basal level that is seen for most mammalian GHs, (3) the accelerated rate of substitution for the exons of the GH gene significantly exceeds that for introns, and (4) the amino acids contributing to the hydrophobic core of GH are strongly conserved when higher primate and other GH sequences are compared, and for coding sequences other than that coding for hydrophobic core residues the rate of substitution for non-synonymous sites (K(A)) is significantly greater than that for synonymous sites (K(S)). In slow loris, as in most non-primate mammals, there is no evidence for duplication of the GH gene, but in marmoset, as in rhesus monkey and man, the putative GH gene is one of a cluster of closely related genes.


Subject(s)
Callithrix/genetics , Evolution, Molecular , Growth Hormone/genetics , Lorisidae/genetics , Animals , Base Sequence , Blotting, Southern , DNA , Molecular Sequence Data , Polymerase Chain Reaction , Sequence Homology, Nucleic Acid , Species Specificity
11.
J Mol Endocrinol ; 23(1): 97-106, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10425451

ABSTRACT

A number of analogues of ovine growth hormone (GH), in which regions of the hormone had been deleted, were produced by site-directed mutagenesis, and characterised by radioimmunoassays and radioreceptor assays. These analogues were based on a previously described variant (oGH1) in which an 8-residue extension replaces the N-terminal alanine of pituitary-derived ovine GH. Three analogues with deletions near the N-terminus were studied, with shorter extensions of 7 or 1-2 residues (oGH14, oGH5) or with the N-terminal sequence Ala-Phe-Pro- of pituitary-derived ovine GH replaced by Thr-Met-Ile-Thr- (oGH11). These modifications had little effect on potency in radioimmunoassays based on a polyclonal antibody and five different monoclonal antibodies (MABs), or in a radioreceptor assay, indicating that the N-terminal sequence was not included in the epitope binding to any of the monoclonal antibodies, or a major epitope binding to the polyclonal antibody, or in receptor binding site 1. A variant in which residues 133-139 were deleted retained full binding to 4 of the 5 MABs, suggesting correct folding, but markedly reduced binding to MAB OA16, suggesting that the epitope for this MAB includes some or all of these residues. This variant also failed to displace about 35% of labelled hormone from the polyclonal antibody studied, suggesting that residues 133-139 may be involved in a major epitope for this antibody. This variant showed slightly lower receptor binding activity than ovine GH. Two other deletion variants - oGH1Delta33-46 (equivalent to the naturally occurring 20K variant of human GH) and oGH1Delta180-191 (lacking the C-terminal 12 residues) showed poor folding efficiency and solubility, and low binding to all MABs except OA15, which has a linear epitope. The results suggest that these variants were incorrectly folded, but interestingly they did retain some activity in the receptor-binding assay (respectively about 5% and 0.5% of the activity of ovine GH itself).


Subject(s)
Growth Hormone/genetics , Animals , Binding, Competitive , Gene Expression Regulation , Genetic Variation , Growth Hormone/isolation & purification , Growth Hormone/metabolism , Mutation , Plasmids , Radioimmunoassay , Radioligand Assay , Sequence Deletion , Sheep
12.
J Control Release ; 53(1-3): 105-17, 1998 Apr 30.
Article in English | MEDLINE | ID: mdl-9741918

ABSTRACT

Sequential block copolymers consisting of tandem repetition of amino acids have been constructed and genetically produced based on the natural repeating structures of silk and elastin protein. Combinations of silklike and elastinlike amino acid sequence blocks in a high molecular weight protein polymer are used to confer properties similar to those observed with hard block and soft block segmented polyurethanes. A certain subset of these silk-elastinlike protein compositions, termed ProLastins, will undergo an irreversible solution to gel transition in physiological, aqueous solution. The transition occurs over time and can be controlled by temperature, solution conditions, and additives which either prevent or promote hydrogen bond-mediated chain crystallization. The process involves no covalent crosslinking. Characterization of the gelling properties of various ProLastin compositions and their ability to release compounds which are incorporated directly into the gels are presented.


Subject(s)
Biopolymers , Drug Carriers , Proteins/administration & dosage , Amino Acid Sequence , Animals , Biocompatible Materials , Calorimetry, Differential Scanning , Molecular Sequence Data , Proteins/chemistry , Viscosity
14.
J Mol Endocrinol ; 19(3): 259-66, 1997 Dec.
Article in English | MEDLINE | ID: mdl-9460647

ABSTRACT

In mammals the structure of pituitary GH is generally strongly conserved, indicating a slow basal rate of molecular evolution. However, on two occasions, during the evolution of primates and of artiodactyls, the rate of evolution has increased dramatically (25- to 50-fold) so that the sequences of human and ruminant GHs differ markedly from those of other mammalian GHs. In order to define further the burst of GH evolution that occurred in artiodactyls we have cloned and characterised the GH gene of red deer (Cervus elaphus) using genomic DNA and a polymerase chain reaction technique. The deduced sequence for the mature GH from red deer is identical to that of bovine GH, indicating that the burst of rapid evolution of GH that occurred in Artiodactyla must have been completed before the divergence of Cervidae and Bovidae and suggesting that the rate of evolution during this burst must have been greater than previously estimated. In other aspects (signal sequence, 5' and 3' sequences, introns and synonymous substitutions in the coding sequence) the red deer GH gene differs considerably from the GH genes of other ruminants. Differences between the signal peptide sequences of red deer and bovid GHs probably explain why N-terminal heterogeneity is seen in bovine, ovine and caprine GHs but not GH from red deer, pig or most other mammals.


Subject(s)
Deer/genetics , Genes/genetics , Growth Hormone/genetics , Amino Acid Sequence , Animals , Artiodactyla/genetics , Base Sequence , Cloning, Molecular , Evolution, Molecular , Female , Growth Hormone/chemistry , Molecular Sequence Data , Phylogeny
15.
Gene ; 163(2): 253-6, 1995 Oct 03.
Article in English | MEDLINE | ID: mdl-7590276

ABSTRACT

The gene encoding growth hormone (GH) has been cloned from a rabbit genomic library, and its sequence has been determined. The rabbit GH gene is similar to other mammalian GH, being comprised of five exons and four introns. As in rodents and artiodactyls, the rabbit GH occurs as a single gene, with no evidence for a cluster of GH-like genes, as is found in primates. The amino acid sequence of rabbit GH is similar to that of pig GH and other conserved mammalian GH, and, like these, differs markedly from the available sequences of ruminant and primate GH. This provides further support for the idea that, in mammals, GH show a slow underlying rate of evolution which has increased markedly on at least two occasions.


Subject(s)
Growth Hormone/genetics , Amino Acid Sequence , Animals , Base Sequence , Chromosome Mapping , Cloning, Molecular , Molecular Sequence Data , Rabbits , Sequence Alignment
18.
Biochim Biophys Acta ; 1261(3): 360-8, 1995 Apr 26.
Article in English | MEDLINE | ID: mdl-7742365

ABSTRACT

The expression levels of coding sequences for pituitary growth hormone, introduced into Escherichia coli by genetic manipulation techniques, vary markedly according to the precise sequence introduced. In order to understand the basis of this variation more fully, we have studied the relationship between the level of expression in E. coli of a series of ovine growth hormone variants and the nucleotide sequences coding for their N-terminal regions. Sequence variation resulted from the introduction of deletions, or site-directed mutations, into a plasmid containing the coding sequence for ovine growth hormone preceded by the initiation codon and 25 bases derived from beta-galactosidase or linker regions of plasmid pUC8. The expression levels of the variants varied from less than 0.01% to over 34% of the total cell protein, indicating that changes in the nucleotide sequence close to the initiation codon had a marked effect on expression level. The results of a comparison of closely related sequences in pairs of plasmids giving poor or good expression are consistent with the hypothesis that poor translation of growth hormone mRNAs is caused by the presence of secondary structures close to the initiation codon. Secondary structures are identified that appear to explain the variation in expression levels.


Subject(s)
Growth Hormone/genetics , Animals , Base Sequence , Cloning, Molecular , Escherichia coli , Gene Expression Regulation , Growth Hormone/chemistry , Growth Hormone/metabolism , Molecular Sequence Data , Plasmids , RNA, Messenger/chemistry , Sheep , beta-Galactosidase/genetics
19.
J Mol Endocrinol ; 11(3): 351-9, 1993 Dec.
Article in English | MEDLINE | ID: mdl-8148043

ABSTRACT

125I-Labelled polypeptide hormones have been extremely valuable for radioimmunoassays, receptor-binding studies and investigation of the processing and metabolism of hormones. However, such externally labelled material has the disadvantage that addition of one or more iodine atoms may alter the properties of the polypeptide. Furthermore, for studies on hormone metabolism and processing, the label may become separated from the hormone or its main breakdown products. Use of internally labelled polypeptides produced by biosynthesis can avoid such problems, but previously such material has usually been of low specific radioactivity, and unsuitable for many purposes. Here we describe the development of a procedure for the production of an internally labelled ovine GH analogue (oGH1) using a plasmid produced by recombinant DNA methods and expression in Escherichia coli. Bacteria were grown in medium containing a low sulphate concentration, and then incubated in medium containing 35SO4(2-) as the sole sulphur source. Under these conditions, the bacteria incorporated 35S into proteins including GH. Purification of such material required considerable modification of previously described methods, because of the need to handle very small amounts of highly radioactive material. The bacteria were lysed using lysozyme, and inclusion bodies were solubilized using 6 M guanidinium chloride. [35S]oGH1 was renatured and then purified by gel filtration on Sephacryl S-100, followed by immunoaffinity chromatography and a second gel filtration step. Material prepared in this way had a specific radioactivity of 6-27 microCi/micrograms, and showed high 'bind-ability' to polyclonal and monoclonal antibodies and to receptors. 35S-Labelled material bound to receptors more effectively than 125I-labelled GH and showed improved stability.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
DNA, Recombinant/genetics , Growth Hormone/genetics , Growth Hormone/isolation & purification , Animals , Cloning, Molecular , Escherichia coli/genetics , Escherichia coli/metabolism , Female , Genetic Variation , Growth Hormone/metabolism , In Vitro Techniques , Inclusion Bodies/metabolism , Microsomes, Liver/metabolism , Pregnancy , Protein Conformation , Rabbits , Sheep , Sulfur Radioisotopes
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