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Biomedical subjects

F W Putnam

Publications and source records attributed to F W Putnam.

At least 91 records · Page 5Linked to original sources
PubMed1986

The clinical phenomenology of multiple personality disorder: review of 100 recent cases.

The clinical syndrome of multiple personality disorder (MPD) is an unusual dissociative condition that has been poorly characterized. In an attempt to better delineate the clinical phenomenology of MPD, 100 recent cases were collected on a 386-item questionnaire completed by clinicians involved in the treatment of MPD patients. This study documents the existence of a clinical syndrome characterized by a core of depressive and dissociative symptoms and a childhood history of significant trauma, primarily child abuse.

Acting Out↗
PubMed1985

Purification of hemopexin and its domain fragments by affinity chromatography and high-performance liquid chromatography.

A method is described for the preparation of apohemopexin from Cohn Fraction IV-4 of human serum by one-step affinity chromatography on a heme-agarose column and separation of its tryptic domain fragments by high-performance liquid chromatography (HPLC). Limited tryptic digestion cleaved human apohemopexin after Arg-216 into half molecules and the N-terminal half was degraded very rapidly, whereas heme-saturated hemopexin was cleaved after Lys-101. These results suggest that hemopexin is composed of two domains that are connected by an exposed histidine-rich hinge-like region in apohemopexin which becomes inaccessible to trypsin in heme-saturated hemopexin. Also described is the preparation of apohemopexin from whole rabbit serum in two steps, heme-affinity chromatography and ion-exchange HPLC, and separation of its tryptic domain fragments by HPLC. Limited tryptic digestion also cleaves rabbit apohemopexin into half-molecules but the N-terminal half is more stable than the C-terminal half in this case. This lends support to the idea of functional differences between domains.

Amino Acids↗
PubMed1985

Automated tandem high-performance liquid chromatographic system for separation of extremely complex peptide mixtures.

We have developed an automated tandem chromatography system, which consists of a combination of ion-exchange column chromatography and reversed-phase column chromatography. The system is composed of two independent high-performance liquid chromatography assemblies, in each of which programmed elution is carried out by a computer-assisted controller. A peptide mixture is applied to an ion-exchange column and is eluted in a stepwise manner. The eluent from the first column is introduced directly into the second, reversed-phase column, which is connected in tandem through a tee tube. After application of two column volumes of the eluent, reversed-phase chromatography is performed by linear gradient elution. Stepwise elution for ion-exchange chromatography and the gradient elution for reversed-phase chromatography are synchronized by a computer program. The resolving power and the reproducibility of the method were tested by using a tryptic digest of human ceruloplasmin [molecular weight 132 000 daltons (132 kDa)]. By this method, the digest was resolved reproducibly into several hundred peaks within 16 h. All of the four glycopeptides expected to be obtained by tryptic digestion were purified easily from the whole digest of the protein. Comparison of the peptide maps between a single-chain and a degraded form of ceruloplasmin facilitated the identification of two tryptic peptides, derived from the carboxyl-terminal regions of 67 kDa and 50 kDa fragments of the degraded form, which lack the carboxyl-terminal arginine and lysine residues, respectively. The method may be applicable to comparative peptide mapping of very large proteins exhibiting molecular microheterogeneity, such as carbohydrate or genetic variants; it also can be used complementarily for sequence support of DNA sequencing as well as for preparative purification of peptides as a strategy of protein sequencing of very large proteins.

Ceruloplasmin↗
PubMed1985

Motor activity and affective illness. The relationship of amplitude and temporal distribution to changes in affective state.

We measured motor activity with a self-contained monitoring device worn on the wrists of affectively ill patients and volunteer normal control subjects. Decreases in the daytime motor activity level were observed in depressed patients, compared with their improved (euthymic) or manic mood states. Moreover, affectively ill patients, even during euthymic periods, showed lower daytime motor activity levels than the control group housed in the same ward. These data provide objective evidence for decreases in motor activity that occur concomitantly with the depressive phase of illness in patients with affective disorder, and fluctuate in patients in euthymic or manic phases.

Adult↗
PubMed1985

Dissociative states in multiple personality disorder: a quantitative study.

Multiple personality disorder (MPD) patients may experience themselves as several discrete alter personalities who do not share consciousness or memories with one another. In this study, we asked whether MPD patients are different from controls in their ability to learn and remember, and their ability to compartmentalize information. MPD patients were not found to differ from controls in overall memory level. Learning of information by MPD patients in disparate personality states did not result in greater compartmentalization than that of which control subjects were capable. However, there were qualitative differences between the cognitive performance of patients and that of controls attempting to role-play alter personalities. Our results suggest that simple confabulation is not an adequate model for the MPD syndrome, and we consider a possible role for state-dependent learning in the phenomenology of MPD.

Adult↗
PubMed1985

Complete amino acid sequence of human hemopexin, the heme-binding protein of serum.

We have determined the complete primary structure of human hemopexin, a plasma beta-glycoprotein that specifically binds one heme with high affinity and transports it to hepatocytes for salvage of the iron. Human hemopexin (Mr approximately equal to 63,000) consists of a single polypeptide chain containing 439 amino acid residues with six intrachain disulfide bridges. The amino-terminal threonine residue is blocked by an O-linked galactosamine oligosaccharide, and the protein has five glucosamine oligosaccharides N-linked to the acceptor sequence Asn-X-Ser/Thr. The 18 tryptophan residues are arranged in four clusters, and 12 of the tryptophans are conserved in homologous positions. Computer-assisted analysis of the internal homology in amino acid sequence indicates that hemopexin consists of two similar halves, thus suggesting duplication of an ancestral gene. Limited tryptic digestion cleaves apohemopexin after arginine-216 into two half-molecules, whereas heme-saturated hemopexin is cleaved after lysine-101. The half-molecules are connected by a histidine-rich hinge-like region that contains two glucosamine oligosaccharides. A structural model for human hemopexin is proposed that is based on these properties and on computer-assisted predictions of the secondary structure and the hydrophilic/hydrophobic character. In this model alpha-helices and beta-turns predominate, and the two halves are connected by an exposed connecting region in apohemopexin that becomes inaccessible to trypsin in hemesaturated hemopexin. Many segments of hemopexin are similar to sequences of other heme proteins, but no overall structural relationship of hemopexin to any other heme protein was identified.

Amino Acid Sequence↗
PubMed1985

Periodicity of leucine and tandem repetition of a 24-amino acid segment in the primary structure of leucine-rich alpha 2-glycoprotein of human serum.

The complete primary structure of the 3.1S leucine-rich alpha 2-glycoprotein (LRG) present in human plasma has been determined. This protein (Mr approximately 45,000) consists of a single polypeptide chain with one galactosamine and four glucosamine oligosaccharides attached. The polypeptide has two intrachain disulfide bonds and contains 312 amino acid residues of which 66 are leucine. The amino acid sequence can be exactly divided into 13 segments of 24 residues each, eight of which exhibit a periodic pattern in the occurrence of leucine, proline, and asparagine. The consensus sequence for the repeating tetracosapeptide unit is Pro-Xaa-Xaa-Leu-Leu-Xaa-Xaa-Xaa-X aa-Xaa-Leu-Xaa-Xaa-Leu-Xaa-Leu-Xaa-Xaa-Asn-Xaa-Leu-Xaa-Xaa-Leu. This periodicity suggests that the unique structure of LRG arose from a series of unequal crossovers of a precursor oligonucleotide sequence that encoded a building block rich in leucine. Overall, the amino acid sequence of LRG is not significantly homologous to the continuous sequence of any protein in the current data base. However, the consensus tetracosapeptide sequence shows strong homology to segments of many mitochondrial proteins, viral envelope proteins, and oncogene proteins that have a high leucine content and transmembrane domains. Tandem repetition of similar segments also occurs in apolipoproteins that have amphipathic helical potential. Prediction of the secondary structure by the Chou-Fasman rules and calculation of the hydrophilic/hydrophobic profile by several methods confirm the tandem repetition of largely hydrophobic structural units; these begin with a beta-turn that leads into an organized structure with alpha-helical or beta-sheet potential. These structural characteristics and the homology to mitochondrial proteins and apolipoproteins suggest that LRG is a membrane-derived or membrane-associated protein containing a series of domains capable of bipolar surface orientation.

Amino Acid Sequence↗
PubMed1984

Purification of glycopeptides of human plasma proteins by high-performance liquid chromatography.

The combination of gel permeation chromatography and high-performance liquid chromatography proves to be very effective for the purification of high-molecular-weight glycopeptides containing a single glycan, that have been difficult to separate by other procedures. In order to facilitate comparison of the chromatographic properties of glycopeptides derived from a variety of proteins and having different structures, identical procedures were used for their purification. The method was applied to a series of human plasma proteins, including immunoglobulin D, ceruloplasmin, hemopexin, beta-2-glycoprotein I, 3.1S alpha-2-leucine-rich glycoprotein, and alpha-1-B-glycoprotein. All the purified glycopeptides were placed in the protein structure of these plasma proteins. In several cases the carbohydrate structure has been determined by collaborating groups. Immunoglobulin D is the first example of a glycoprotein whose entire primary structure has been defined by utilizing a a single protein source. Furthermore, hemopexin and 3.1S alpha-2-leucine-rich glycoprotein were both found to contain GalN oligosaccharide, which had not previously been identified in these proteins. The method was also used to identify the oligosaccharide that is missing in a carbohydrate variant of ceruloplasmin.

Amino Acid Sequence↗
PubMed1984

Complete amino acid sequence of human plasma beta 2-glycoprotein I.

We have determined the complete amino acid sequence of beta 2-glycoprotein I (Mr, congruent to 50,000), a human plasma protein that is associated with lipids and binds to platelets but whose function is not yet known. The protein consists of 326 amino acids and has five attached glucosamine-containing oligosaccharides. The protein is rich in cysteine and proline, and the sequence is notable for the frequent occurrence of Cys-Pro linkages at regular intervals. Computerized analysis of the sequence reveals five consecutive homologous segments in which cysteine, proline, and tryptophan appear to be highly conserved. This suggests that beta 2-glycoprotein I may have evolved by repeated duplications of a gene coding for a 60-amino acid segment of protein.

Amino Acid Sequence↗
PubMed1984

Structural model of human ceruloplasmin based on internal triplication, hydrophilic/hydrophobic character, and secondary structure of domains.

A molecular model for the structure of human ceruloplasmin is proposed that is based on the determination of the complete amino acid sequence, studies of the products of limited proteolytic cleavage, calculations of the hydrophilic/hydrophobic character (hydropathy profile), and predictions of the local secondary structure. This multicopper oxidase (Mr approximately 132,000) consists of a single polypeptide chain (1046 amino acid residues) with four attached glucosamine oligosaccharides. Computer-assisted statistical analysis of the internal repetition in the amino acid sequence confirms that the entire polypeptide chain is divided into three contiguous homology units, each containing about 350 amino acid residues. Each homology unit is subdivided into three domains, designated A1, A2, and B, that differ in structure and probably in function. Calculations of the hydropathy profile and predictions of the secondary structure support a molecular model based on internal repetition of three homology units and help to identify characteristic features of the interdomain junctions. The alignment scores for internal duplication of pairings of the three homology units of ceruloplasmin exceed the scores yet reported for contiguous internal duplication of any other protein. This highly significant evidence for intragenic repetition suggests that the ceruloplasmin molecule evolved by tandem triplication of ancestral genes coding for a primordial copper oxidase.

Amino Acid Sequence↗
PubMed1984

Single-chain structure of human ceruloplasmin: the complete amino acid sequence of the whole molecule.

We have determined the amino acid sequence of the amino-terminal 67,000-dalton (67-kDa) fragment of human ceruloplasmin and have established overlapping sequences between the 67-kDa and 50-kDa fragments and between the 50-kDa and 19-kDa fragments. The 67-kDa fragment contains 480 amino acid residues and three glucosamine oligosaccharides. These results together with our previous sequence data for the 50-kDa and 19-kDa fragments complete the amino acid sequence of human ceruloplasmin. The polypeptide chain has a total of 1,046 amino acid residues (Mr 120,085) and has attachment sites for four glucosamine oligosaccharides; together these account for the total molecular mass of human ceruloplasmin (132 kDa). The sequence analysis of the peptides overlapping the fragments showed that one additional amino acid, arginine, is present between the 67-kDa and 50-kDa fragments, and another, lysine, is between the 50-kDa and 19-kDa fragments. Only two apparent sites of amino acid interchange have been identified in the polypeptide chain. Both involve a single-point interchange of glycine and lysine that would result in a difference in charge. The results of the complete sequence analysis verified that human ceruloplasmin is composed of a single polypeptide chain and that the subunit-like fragments are produced by proteolytic cleavage during purification (and possibly also in vivo).

Amino Acid Sequence↗
PubMed1984

Structure of human hemopexin: O-glycosyl and N-glycosyl sites and unusual clustering of tryptophan residues.

The primary structure of human hemopexin is being deduced from sequence analysis of a series of peptides obtained from chemical and enzymatic digests of the protein. Human hemopexin consists of about 440 amino acid residues. It has five sites of attachment of glucosamine oligosaccharides at the signal sequence of Asn-X-Thr/Ser. A unique structural feature is the virtual blocking of the amino-terminal threonine residue, which is O-linked to a galactosamine oligosaccharide that has not previously been identified in this protein. The galactosamine oligosaccharide and one glucosamine oligosaccharide are located in the amino-terminal region, three of the glucosamine oligosaccharides are in the middle region, and one glucosamine oligosaccharide is in the carboxyl-terminal region of the protein. Two of the five glucosamine oligosaccharides are present in a histidine-rich sequence of the middle region of the protein, in which the histidines flank beta-turns presumably at the surface of hemopexin. Clusters of tryptophan residues occur in four regions, each of which contains three or four tryptophan residues separated by 0-12 other residues. This clustering is significant because both histidine and tryptophan have been implicated in the binding of heme. A computer analysis did not identify significant matches of human hemopexin to any protein, including cytochromes and other heme-binding proteins, which suggests that the human hemopexin gene evolved from a unique primordial gene differing from those of other heme-binding proteins.

Amino Acid Sequence↗
PubMed1984

Multiple personality disorder in a hospital setting.

Multiple personality disorder (MPD) should be considered in cases where there have been multiple diagnoses, failure of conventional treatments, a mixture of psychiatric and somatic symptoms, and/or extremely rapid shifts in symptoms and level of function. Proper diagnosis and treatment often leads to a significant amelioration in symptoms and increase in level of function for a patient previously refractory to treatment.

Adult↗
PubMed1983

Separation of limited tryptic fragments of human ceruloplasmin by gel-permeation high-performance liquid chromatography.

Limited tryptic proteolysis of human ceruloplasmin rapidly produces several large, protease-resistant fragments, suggesting that the molecule consists of several domains. In order to locate the sites of proteolytic cleavage in the whole molecule, we used gel-permeation high-performance liquid chromatography to determine the optimum conditions for fragment separation. Using a buffer containing 8 M urea, the 67,000-daltons tryptic fragment from single-chain ceruloplasmin was isolated in a sufficiently pure state for amino acid sequence analysis to determine its location in the uncleaved molecule. These results have been used in conjunction with amino acid sequence data to develop a schematic model of the domain structure of human ceruloplasmin.

Ceruloplasmin↗
PubMed1983

Two-dimensional high-performance liquid chromatography and chemical modification in the strategy of sequence analysis. Complete amino acid sequence of the lambda light chain of human immunoglobulin D.

Rapid high-performance liquid chromatographic procedure forms part of the strategy for determining the amino acid sequence of proteins. It was applied to the light chain of an immunoglobulin D, and the result, together with previous data on the sequence of the heavy chain, established the complete covalent structure of a human IgD immunoglobulin. We aimed for rapid purification of both small and large peptides. The two-step chromatography system ("two-dimensional chromatography") consists of a combination of macroreticular cation-exchange chromatography as the first dimension and reversed-phase chromatography as the second. This procedure was used for the systematic separation of the tryptic peptides of the light chain. In order to obtain overlapping of the tryptic peptides, chemical modifications of the light chain and reversed-phase chromatography were found to be the most reliable path toward the sequence analysis and greatly accelerated the determination of the light chain.

Amino Acid Sequence↗
PubMed1983

Purification of cyanogen bromide fragments from beta-2-glycoprotein I by high-performance liquid chromatography.

Reversed-phase high-performance liquid chromatography (HPLC) with a linear elution gradient of 1-propanol in 0.1% aqueous trifluoroacetic acid was used to purify cyanogen bromide fragments from the human plasma protein beta-2-glycoprotein I. The fragments, ranging from 33 to 119 amino acids in length, were obtained in sufficient purity and yield for automated sequence analysis and enzymatic digestion. One fragment, which contained most of the carbohydrate, could be isolated as an aggregate or as two heterogeneous monomers. The elution of this fragment was much earlier than expected on the basis of its retention coefficient calculated from amino acid composition. Our results demonstrate the applicability of recently developed HPLC techniques to the separation of cyanogen bromide fragments from a carbohydrate-rich glycoprotein whose structure is not completely known.

Chromatography, Gel↗