Wilson Disease: A Case Report of Psychosis Preceding Parkinsonism

BACKGROUND A first psychotic episode requires the exclusion of toxic-metabolic, inflammatory, infective, and neoplastic causes. Wilson disease is a rare, autosomal recessive disorder of copper metabolism and can present with neuropsychiatric symptoms secondary to copper accumulation in the brain. CASE REPORT We describe the case of a 48-year-old man with parkinsonism on a background of longstanding schizophrenia and psychotic depression in the setting of previously undiagnosed Wilson disease. The common history of neuropsychiatric disturbance and neuroleptic use complicated the assessment of parkinsonism. However, close attention to the temporal appearance of symptoms and signs differentiated his case from drug-induced parkinsonism, which commonly develops hours to weeks after commencement or uptitration of antipsychotic medication. The early features of sialorrhea and dysarthria were also atypical for idiopathic Parkinson disease. The diagnosis was confirmed by serum copper testing and supported by Kayser-Fleischer rings on bedside ophthalmological examination. Magnetic resonance imaging (MRI) of the brain demonstrated copper accumulation in the basal ganglia and pons, contributing to the characteristic neurological manifestations of an akinetic-rigid syndrome with dysarthria. CONCLUSIONS Serum copper testing is easily obtained and should be considered as part of the first-line investigations for new neuropsychiatric disturbances. Although rare, Wilson disease, if diagnosed early, is a potentially treatable and reversible cause of psychosis. With advanced disease, extrapyramidal findings on examination correlate with MRI brain changes, aiding the clinical assessment in differentiating the disease from drug-induced parkinsonism.

Mitochondrial DNA 13513G>A Mutation Causing Leber Hereditary Optic Neuropathy Associated With Adult-Onset Renal Failure

BACKGROUND

Leber hereditary optic neuropathy (LHON) is one of the more common mitochondrial diseases and is rarely associated with mitochondrial renal disease. We report 3 unrelated patients with a background of adult-onset renal failure who presented to us with LHON and were shown to have a heteroplasmic mitochondrial DNA mutation (m.13513G>A).

METHODS

Retrospective chart review.

RESULTS

All 3 patients had a background of chronic renal failure and presented to us with bilateral optic neuropathy (sequential in 2) and were found to have heteroplasmic m.13513G>A mutations in the MT-ND5 gene. Two of the patients were females (aged 30 and 45 years) with chronic kidney disease from their 20s, attributed to pre-eclampsia, one of whom also had diabetes and sudden bilateral hearing loss. One patient was a male (aged 54 years) with chronic kidney disease from his 20s attributed to IgA nephropathy. His mother had diabetes and apparently sudden bilateral blindness in her 70s. Renal biopsy findings were variable and included interstitial fibrosis, acute tubular necrosis, focal segmental glomerulosclerosis, and IgA/C3 tubular casts on immunofluorescence. Mild improvements in vision followed treatment with either idebenone or a combination supplement including coenzyme Q10, alpha-lipoic acid, and B vitamins.

CONCLUSIONS

Our cases expand the clinical syndromes associated with m.13513G>A to include bilateral optic neuropathy and adult-onset renal disease. This highlights that in patients with bilateral, especially sequential, optic neuropathy a broad approach to mitochondrial testing is more useful than a limited LHON panel. Mitochondrial diseases present a diagnostic challenge because of their clinical and genetic variability.

Capturing nystagmus in the emergency room: posterior circulation stroke versus acute vestibular neuritis

OBJECTIVES

To compare acute nystagmus characteristics of posterior circulation stroke (PCS) and acute vestibular neuritis (AVN) in the emergency room (ER) within 24 h of presentation.

METHODS

ER-based video-nystagmography (VNG) was conducted, recording ictal nystagmus in 101 patients with PCS (on imaging) and 104 patients with AVN, diagnosed on accepted clinical and vestibular test criteria.

RESULTS

Patients with stroke in the brainstem (38/101, affecting midbrain (n = 7), pons (n = 19), and medulla (n = 12)), cerebellum (31/101), both (15/101) or other locations (17/101) were recruited. Common PCS territories included posterior-inferior-cerebellar-artery (41/101), pontine perforators (18/101), multiple-territories (17/101) and anterior-inferior-cerebellar-artery (7/101). In PCS, 44/101 patients had no spontaneous nystagmus. Remaining PCS patients had primary position horizontal (44/101), vertical (8/101) and torsional (5/101) nystagmus. Horizontal nystagmus was 50% ipsiversive and 50% contraversive in lateralised PCS. Most PCS patients with horizontal nystagmus (28/44) had unidirectional "peripheral-appearing" nystagmus. 32/101 of PCS patients had gaze-evoked nystagmus. AVN affected the superior, inferior or both divisions of the vestibular nerve in 55/104, 4/104 and 45/104. Most (102/104) had primary position horizontal nystagmus; none had gaze-evoked nystagmus. Two inferior VN patients had contraversive torsional-downbeat nystagmus. Horizontal nystagmus with SPV ≥ 5.8 °/s separated AVN from PCS with sensitivity and specificity of 91.2% and 83.0%. Absent nystagmus, gaze-evoked nystagmus, and vertical-torsional nystagmus were highly specific for PCS (100%, 100% and 98.1%).

CONCLUSION

Nystagmus is often absent in PCS and always present in AVN. Unidirectional 'peripheral-appearing' horizontal nystagmus can be seen in PCS. ER-based VNG nystagmus assessment could provide useful diagnostic information when separating PCS from AVN.

A Window Into the Whole Story: Temporal Bone Plasmacytoma Presenting With a Mobile Third Window

A 63-year-old man presented with imbalance when coughing due to a respiratory tract infection. He had a history of multiple myeloma with a plasmacytoma of the left temporal bone. Examination revealed a positive leftward head impulse test, no spontaneous nystagmus, left-beating positional nystagmus, and left-beating Valsalva-induced nystagmus. Videonystagmography, audiology, and comprehensive vestibular function tests revealed a subtotal left peripheral audio-vestibular loss. Temporal bone computed tomography showed an unchanged bony erosion of the left labyrinth from 2 years prior. Vertigo subsided after treatment of the respiratory tract infection. Although no tumor progression was evident, coughing had triggered a preexisting third mobile window to declare itself. Laryngoscope, 131:E966-E969, 2021.

Invasive Fungal Sinusitis Presenting as Acute Posterior Ischemic Optic Neuropathy

Invasive fungal sinusitis causes painful orbital apex syndrome with ophthalmoplegia and visual loss; the mechanism is unclear. We report an immunocompromised patient with invasive fungal sinusitis in whom the visual loss was due to posterior ischaemic optic neuropathy, shown on diffusion-weighted MRI, presumably from fungal invasion of small meningeal-based arteries at the orbital apex. After intensive antifungal drugs, orbital exenteration and immune reconstitution, the patient survived, but we were uncertain if the exenteration helped. We suggest that evidence of acute posterior ischaemic optic neuropathy should be a contra-indication to the need for orbital exenteration in invasive fungal sinusitis.

Neuro-ophthalmology of invasive fungal sinusitis: 14 consecutive patients and a review of the literature

BACKGROUND

Invasive fungal sinusitis is a rare condition that usually occurs in immunocompromised patients and often presents as an orbital apex syndrome. It is frequently misdiagnosed on presentation and is almost always lethal without early treatment.

DESIGN

Retrospective case series of 14 consecutive patients with biopsy-proven invasive fungal sinusitis from four tertiary hospitals.

PARTICIPANTS

Fourteen patients (10 men and 4 women; age range 46-82 years).

METHODS

Retrospective chart review of all patients presenting with invasive fungal sinusitis between 1994 and 2010 at each hospital, with a close analysis of the tempo of the disease to identify any potential window of opportunity for treatment.

MAIN OUTCOME MEASURES

Demographic data, background medical history (including predisposing factors), symptoms, signs, radiological findings, histopathological findings, treatment approach and subsequent clinical course were recorded and analysed.

RESULTS

Only one patient was correctly diagnosed at presentation. Only two patients were not diabetic or immunocompromised. The tempo was acute in two patients, subacute in nine patients and chronic in three patients. In the subacute and chronic cases, there was about 1 week of opportunity for treatment, from the time there was a complete orbital apex syndrome, and still a chance for saving the patient, to the time there was central nervous system invasion, which was invariably fatal. Only two patients survived - both had orbital exenteration, as well as antifungal drug treatment.

CONCLUSIONS

Invasive fungal sinusitis can, rarely, occur in healthy individuals and should be suspected as a possible cause of a progressive orbital apex syndrome.

Spinal root and plexus hypertrophy in chronic inflammatory demyelinating polyneuropathy

MRI was performed on the spinal roots, brachial and lumbar plexuses of 14 patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Hypertrophy of cervical roots and brachial plexus was demonstrated in eight cases, six of whom also had hypertrophy of the lumbar plexus. Of 11 patients who received gadolinium, five of six cases with hypertrophy and one of five without hypertrophy demonstrated enhancement. All patients with hypertrophy had a relapsing-remitting course and a significantly longer disease duration. Gross onion-bulb formations were seen in a biopsy of nerve from the brachial plexus in one case with clinically evident nodular hypertrophy. We conclude that spinal root and plexus hypertrophy may be seen on MRI, particularly in cases of CIDP of long duration, and gadolinium enhancement may be present in active disease.

Musculoskeletal causes of spinal axis compromise: beyond the usual suspects

The majority of cases of spinal canal compromise are caused by common pathologic conditions, including degenerative spondylosis, infection, trauma, and metastatic disease. However, there are other causes of spinal canal compromise that, though unusual, may be seen in everyday practice. Congenital abnormalities of the spine that may produce spinal canal compromise include the os odontoideum, hemivertebra, diastematomyelia, and achondroplasia. Arthritides and enthesopathies such as rheumatoid arthritis, ankylosing spondylitis, synovial cysts of the facet joint, calcium pyrophosphate dihydrate deposition or hydroxyapatite deposition, and ossification of the posterior longitudinal ligament or ligamentum flavum may lead to narrowing of the spinal canal. Primary spinal tumors and tumorlike lesions such as hemangioma, aneurysmal bone cysts, osteochondroma, and osteoblastoma may also cause spinal canal stenosis. Finally, Paget disease of bone may compromise the spinal cord. Radiologists should be aware of these unusual musculoskeletal causes of spinal canal compromise and their radiologic and clinical features.

Hypoglossal nerve palsy: a segmental approach

Hypoglossal nerve (cranial nerve XII) palsy is uncommon. Damage to this nerve produces characteristic clinical manifestations, of which unilateral atrophy of the tongue musculature is the most important. When these features are recognized, the radiologist, armed with knowledge of the normal anatomy of the area, can focus on each segment of the nerve in search of a cause. The hypoglossal nerve is divided into five segments: the medullary, cisternal, skull base, nasopharyngeal/oropharyngeal carotid space, and sublingual segments. Because each segment is usually affected by different disorders, localizing a lesion to a particular segment allows the radiologist to narrow the differential diagnosis. In this way, the most efficient imaging strategy for evaluation of the symptoms can be developed. Both computed tomography and magnetic resonance imaging are useful in assessing dysfunction of the hypoglossal nerve; the choice depends on the status of the patient and the preference of the radiologist.

PCR amplification of partial mRNA sequences encoding the alpha- and beta-globin chains of the bivalve mollusc Anadara trapezia: correction of the C-terminal amino acid sequence of the alpha-chain

1. PCR was carried out on cDNA which had been synthesized from poly(A)+ RNA extracted from A. trapezia red blood cells. 2. A 348 bp product encoding the C-terminal region of the alpha-globin chain and another product encoding a portion of the beta-globin chain were isolated. 3. The C-terminal alpha-chain sequence, encoded by the cDNA, differs from the previously published sequence and these changes improve the alignment of this chain with the other globin chains of this organism.

A minor globin gene of the bivalve mollusc Anadara trapezia

A minor haemoglobin gene was isolated from an Anadara trapezia genomic library using a synthetic oligonucleotide probe based on the identical amino acid sequence of the F-helical region of all the major Anadara globins previously sequenced. The amino acid sequence inferred from the coding region of the gene indicated that it is different from that of the three major chains alpha, beta and gamma, but most like the beta-chain. This beta-variant sequence shows 100% homology in the conserved F-helix region. The minor gene was found to contain two long intervening sequences, 1214 bp and 1435 bp, longer than those present in the genes for vertebrate globins or leghaemoglobins but shorter than those in myoglobin genes.

Oestrogen sulfotransferase: molecular cloning and sequencing of cDNA for the bovine placental enzyme

The female sex hormone, oestrogen, plays a central role in breast cell proliferation in both the normal and malignant state. It controls transcription from several genes, including that for the progesterone receptor, and in endometrial tissue, via this receptor, it controls the gene for the enzyme oestrogen sulfotransferase. This enzyme may control the level of the oestrogen receptor by sulfurylating free oestradiol. To study the mode of transcriptional control exercised by oestrogen, bovine oestrogen sulfotransferase cDNA has been cloned and the nucleotide sequence determined. The message, of which 1812 bases have been sequenced, contains an open reading frame of 885 bases which encode a protein of 295 amino acids and a maximum apparent molecular weight of 34,600. The deduced protein sequence is supported by existing peptide sequence data and appears to contain a steroid-binding region. Some physico-chemical characteristics of the enzyme appear to differ markedly from those previously reported.

Oestrogen sulfotransferase: isolation of a high specific activity species from bovine placenta

During the course of a study of the control of expression of steroid-binding proteins in human mammary cancer oestrogen sulfotransferase was isolated from bovine placenta. By a combination of salt precipitation and ion-exchange and gel-permeation chromatography two forms of the enzyme were isolated. The forms, which apparently differ only in charge, have specific activities 100-300 times greater than has previously been reported for the enzyme. Partial peptide sequences of these enzymes are presented.

Amino acid sequence of the beta-chain of the tetrameric haemoglobin of the bivalve mollusc, Anadara trapezia

The amino acid sequence of the beta-chain of the principal haemoglobin from A. trapezia has been determined. The sequence was deduced from the sequences of tryptic peptides, which were fractionated using highperformance liquid chromatography and peptide mapping. Additional sequence data, particularly for the large tryptic peptides, was obtained from enzyme digests of both cyanogen bromide fragments and large citraconyltryptic peptides. The beta-chain has 151 residues which is longer than all the other sequenced haemoglobin chains except the alpha-chain of A. trapezia, which is 153 residues in length. The residues corresponding to those normally in the D helix are absent in this beta-chain. The additional residues are contributed by an extension of the N-terminal region, which was also found to be acetylated. Comparison of the beta-chain amino acid sequence with that of the alpha-chain of A. trapezia, the dimeric chain of A. trapezia, and the dimeric chain of A. broughtonii showed 53% identity in each case. In the E and F helices, the homology is particularly noticeable. There is 100% homology in the F helix of all four chains. The dimeric globin of A. trapezia also shows 100% homology with the beta-chain in the E helix, while the alpha-chain shows 75%. If the tertiary structure of the alpha- and beta-chains of A. trapezia haemoglobin is the same as that of horse haemoglobin, then there are many changes in the alpha 1 and beta 2 contact site residues.

Amino acid sequence studies on sheep liver fructose-bisphosphatase. II. The complete sequence

The cyanogen bromide fragments of S-carboxymethylated fructose-bisphosphatase were purified. The amino acid sequences of the small fragments were determined by the dansyl-Edman method. The large fragments were subjected to proteolytic digestion to give smaller peptides more amenable for purification and sequencing by similar methods. Enzyme digests of the S-carboxymethylated enzyme gave overlap peptides containing the methionine residues. In conjunction with the amino acid sequence of the 60-residue N-terminal fragment previously determined on the S-peptide released by limited proteolysis with subtilisin the complete sequence of 336 residues was deduced. The sequence has been compared with the 335 residue sequence of pig kidney fructose-bisphosphatase and some areas of sequence for rabbit liver enzyme. The strong homology previously noted for the S-peptide sequence is maintained for the complete enzyme with only 34 changes in 336 residues when comparing the pig and sheep enzymes.

Carboxymethylation of thiol groups in ovalbumin: implications for proteins that contain both thiol and disulfide groups

The cysteine residues of hen ovalbumin were S-carboxymethylated with non-radioactive iodoacetic acid under various conditions by altering the pH at which the protein was denatured in 8 M urea, by using different molar ratios of non-radioactive iodoacetic acid to cysteine and by varying the time at which carboxymethylation was commenced after denaturing conditions had been applied. Under the various conditions, the thiol groups were carboxymethylated to different extents, the residual thiol groups being measured by reaction with 5,5'-dithiobis(2-nitrobenzoic acid) in the presence of sodium dodecyl sulfate. When ovalbumin is carboxymethylated in alkaline urea, it unfolds slowly and the carboxymethylation is incomplete even with 150-fold excess iodoacetic acid. The known rapid thiol-disulfide exchange that occurs at alkaline pH values makes this method of carboxymethylation unsuitable as a preliminary step for blocking the native cysteine residues of ovalbumin before reduction and labelling the thiol groups formed by reduction of the disulfide bonds. Titration of the thiol groups of ovalbumin in 6 M guanidine hydrochloride or 1% (w/v) sodium dodecyl sulfate at pH 8.2 with 5,5'-dithiobis(2-nitrobenzoic acid) is more rapid than in 8 M urea and these solvents would be preferable for studies of the disulfide-bonded sequences. Denaturation of ovalbumin in acidic 8 M urea is a very rapid process, and under mild acid conditions thiol-disulfide interchange is much slower. Subsequent carboxymethylation of the cysteine residues at alkaline pH with 150-fold excess iodoacetic acid results in complete carboxymethylation and the carboxymethylated ovalbumin can be reduced and labelled with radioactive iodoacetic acid with specific labelling of the half-cystine residues involved in the disulfide bond. The results are discussed in relation to the allocation of half-cystine residues in other protein systems that contain both thiol and disulfide groups.

Uridine and inosine: pressor nucleosides from man, rat and dog

Short-acting pressor compounds isolated from rat kidney, brain, heart and spleen have been identified as inosine and uridine by gas chromatography, mass spectrometry, high pressure liquid chromatography and analysis of ultraviolet spectra. Inosine was further identified by nuclear magnetic resonance. These compounds have also been found in kidneys from hypertensive man, rejected renal transplants and dog and beef kidney. Tissues were extracted by acid ethanol extraction followed by gel filtration and high voltage paper electrophoresis. Compounds found to be pressor in the anaesthetised rat resisted proteolytic enzymes, boiling for 10 min, extremes of pH and incubation with plasma from the source species for up to 20 min. The pressor effects of bolus injections of active gel filtration fractions, uridine and inosine were short-lived with a maximum effect at 5-6 s. Intravenous (I.V.) infusions of extracts gave a sustained pressor response without a concurrent change in heart rate. The effect on blood pressure was not accompanied by increased heart rate and persisted when the pressor effects of angiotensin II, noradrenaline and 5-hydroxy-tryptamine were blocked pharmacologically.

Amino acid sequences containing cysteine or cystine residues in ovalbumin from eggs of the quail Coturnix coturnix japonica

Ovalbumin isolated from eggs of the Japanese quail, C. c. japonica, was subjected to limited proteolysis by subtilisin to give plakalbumin and then fractionated on Sephadex G75 in acid-urea to give plakalbumin S-protein and S-peptide. The plakalbumin peptide was recovered, oxidized with performic acid, and the sequence of amino acids determined from the peptides formed by enzyme digestion. There were two cysteine residues in the 33-residue sequence. The ovalbumin was also oxidized with performic acid and digested with thermolysin and pepsin before isolating, from a sulfonated polystyrene column, the acidic cysteic acid peptides, as well as acetylated N-terminal peptides and phosphorylated peptides, and determining their amino acid sequence. Additional peptide sequences containing cysteine or half-cystine were characterized. Quail ovalbumin was reduced and carboxymethylated with [2-14C]iodoacetic acid. Peptides containing labelled S-carboxymethylcysteine residues were isolated from thermolytic digests of the carboxymethylated ovalbumin by paper ionophoresis and chromatography. Their amino acid sequence was determined and five different sequences involving labelled S-carboxymethylcysteine residues were established. The presence of two half-cystine residues and the location of the disulfide bond were shown by blocking the cysteine residues with non-radioactive iodoacetic acid, reducing the disulfide bond and labelling the half-cystine residues with [2-14C]iodoacetic acid. After thermolytic digestion of the protein, radioactive peptides were isolated by paper ionophoresis and chromatography. These studies have thus shown that quail ovalbumin contains one cystine residue and three cysteine residues, which is one residue of cysteine less than in ovalbumin from the hen (Gallus gallus domesticus). There is strong homology in the amino acid sequences of hen ovalbumin and quail ovalbumin determined in these investigations.

Amino acid sequence studies on sheep liver fructose-bisphosphatase. I. The S-peptide

Fructose-bisphosphatase has been isolated from sheep liver using affinity-elution chromatography from carboxymethylcellulose as the final purification step. The purified enzyme was homogeneous by disc gel electrophoresis. Digestion with subtilisin yielded the N-terminal S-peptide similar to that reported for the rabbit and pig. The peptide has an acetylated amino terminal residue and the following sequence deduced from a study of the tryptic and cyanogen bromide peptides: Ac-Thr-Asp-Glu-Ala-Pro-Phe-Asp-Thr-Asn-Ile-Val-Thr-Val-Thr-Arg-Phe-Val-Met-Glu-Glu-Gly-Arg-Lys-Ala-Arg-Gly-Thr-Gly-Glu-Met-Thr-Gln-Leu-Leu-Asn-Ser-Leu-Cys-Thr-Ala-Val-Lys-Ala-Ile-Ser-Thr-Ala-Val-Arg-Lys-Ala-Gly-Ile-Ala-His-Leu-Tyr-Gly-Ile-Ala. The sheep liver S-peptide sequence shows only six changes in 60 residues and three changes in 56 residues compared with the sequences of the rabbit and pig S-peptides respectively.

Amino acid sequences containing cysteine or half-cystine residues in beta-glucuronidase

Amino acid analysis of oxidized or reduced and carboxymethylated beta-glucuronidase have shown the presence of 24 cysteic acid or S-carboxymethylcysteine residues respectively per mole of the tetrameric enzyme. Titration of sulfhydryl groups gave eight cysteine residues, and by difference 16 half-cystine residues per mole. Six peptides containing radiolabelled cysteine residues were isolated from pepsin and chymotrypsin digest of reduced and S-carboxymethylated beta-glucuronidase by ion-exchange chromatography or gel filtration, followed by paper ionophoresis and paper chromatography. The peptides were analysed for amino acids and sequenced by the dansyl-Edman procedure. Peptides containing cysteic acid were selectively recovered from thermolysin digests of performic acid-oxidized glucuronidase. The amino acid sequences confirmed that there were only six different peptide sequences containing either cysteine or half-cystine residues in the tetrameric enzyme, supporting the presence of four identical subunits. These sequences wer: (A)-Val-Asx-Val-Ile-Cys-Val-Asx-Ser-Tyr- (B)-Gly-Asx-Leu-Cys-Ser-Gly- (C)-Phe-Val-Val-Ile-Asx-Glx-Cys-Pro-Gly-Val-Gly- (D)-Val-Val-Cys-Leu- (E)-Gln-Ser-Gly-Cys-Leu-Val-Lys-Gly-Tyr- (F)-Cys-Asp-Arg-Tyr-Gly-Ile-Val-Val-.

Myoglobins of cartilaginous fishes. II. Isolation and amino acid sequence of myoglobin of the shark Mustelus antarcticus

Myoglobin isolated from red muscle of the gummy shark M. antarcticus was purified by gel filtration and ion-exchange chromatography on carboxymethyl cellulose in 8 M urea-thiol buffer. Amino acid analysis and sequence determination showed 148 amino acid residues. The amino terminal residue is acetylated as shown by nuclear magnetic resonance and mass spectrographic analysis of an N-terminal peptide. There is a deletion of four residues at the amino terminal end as well as one residue in the CD interhelical area relative to other myoglobins. These overall differences were also found previously in myoglobin of Heterodontus portusjacksoni. The complete amino acid sequence has been determined following digestion with trypsin, chymotrypsin, thermolysin, staphylococcal protease and cyanogen bromide. Sequences of purified peptides were determined by the dansyl-Edman procedure. The amino acid sequence showed approximately 88 differences from mammalian, monotreme, bird and tuna myoglobins, slightly more than previously reported for H. portusjacksoni usually considered a more primitive animal. There were 24 residues common to both shark myoglobins that were different from those present in other myoglobins. The sequence has been compared to the myoglobin of yellowfin tuna and other myoglobins.

Myoglobin of the shark Heterodontus portusjacksoni: isolation and amino acid sequence

Myoglobin isolated from red muscle of the shark H. portusjacksoni was purified by ion-exchange chromatography on sulfopropyl-Sephadex and gel-filtration. Amino acid analysis and sequence determination showed 148 amino acid residues. The amino terminal residue is acetylated as shown by mass spectrographic analysis of N-terminal peptides. There is a deletion of four residues at the amino terminal end as well as one residue in the CD interhelical area relative to other myoglobins. The complete amino acid sequence has been determined following digestion with trypsin, chymotrypsin, pepsin and staphylococcal protease. Sequences of the purified peptides were determined by the dansyl-Edman procedure. The amino acid sequence showed approximately 85 differences from mammalian, monotreme and bird myoglobins. The date of divergence of the shark H. portusjacksoni from these other orders was estimated at 450 +/- 16 million years, based on the number of amino acid differences between species and allowing for multiple mutations during the evolutionary period. This estimate agrees well with similar estimates made using alpha- and beta-globin sequences, in contrast to widely differing estimates of dates of divergence for monotremes using the same three globin chains. Compared with myoglobins from species previously studied, there are many more differences in amino acid sequences, and in many positions residues are found that are more characteristic of alpha- and beta-globins, suggesting a conservation of residues over a long period of evolutionary time. There are fewer stabilizing hydrogen bonds and salt-linkages than in other myoglobins.

Hb I alpha16 Lys leads to Glu and Hb Broussais alpha90 Lys leads to Asn in Australian families

This paper describes the finding of Hb 1 alpha16 Lys leads to Glu and Hb Broussais alpha90 Lys leads to Asn in Australian families. Neither of these variants has been previously described in the Australian population. The variants were detected in an electrophoretic screening of 2500 blood samples. Both variants were clinically silent. The haematological parameters were within normal limits and the peripheral blood morphology was normal.

A correction and extension of the acetylated amino terminal sequence of ovalbumin

The acetylpeptides derived from S-carboxymethylovalbumin by cyanogen bromide and chymotrypsin have been isolated and shown by enzyme digestion and the dansyl-Edman method to fit the sequence acetyl-Gly-Ser-Ile-Gly-Ala-Ala-Ser-Met-Glu-Phe. This corrects the order of the third and fourth residues in the five-residue sequence given by Narita and Ishii [J. Biochem. (Tokyo), 1962, 52, 367--73]. The overlap of the C-terminal sequence of this extended sequence with the six-residue N-terminal sequence surrounding a half-cystine residue in ovalbumin gives the N-terminal sequence for ovalbumin as acetyl-Gly-Ser-Ile-Gly-Ala-Ala-Ser-Met-Glu-Phe-Cys-Phe-Asp-Val-Phe-Lys with residue 11 a cysteine residue.

Amino acid sequences containing half-cystine residues in ovalbumin

Ovalbumin is known to have six half-cystine residues with four thiol groups and one disulfide bond.

Amino acid sequence of the N-terminal 108 amino acid residues of the B chain of subcomponent C1q of the first component of human complement

The amino acid sequence of the N-terminal 108 residues of the B chain of subcomponent C1q of the first component of human complement was determined. The B chain has a blocked N-terminal amino acid, which was judged to be 5-oxopyrrolidine-2-carboxylic acid. A collagen-like region of 84 residues was found, which started at position B-6, and all of the six hydroxylysine residues and 12 hydroxyproline residues present in the chain were found in this region. Four of the six hydroxylysine residues may be glycosylated. The repeating nature of the collagen-like region is broken at position B-9, where alanine is found in a position where glycine would be expected. The exact position of the interchain disulphide bond joining the A and B chains of human subcomponent C1q was shown to be between residues A4 and B4.

Haemoglobins of the shark, Heterodontus portusjacksoni. III. Amino acid sequence of the beta-chain

The amino acid sequence of the beta-chain of the principal haemoglobin from the shark H. portusjacksoni has been determined. The chain has 141 residues, the same as that of mammalian alpha-chains and less than the 146 residues of mammalian beta-chains or the 148 residues of the alpha-chain from the tetrameric shark haemoglobin. The sequence was deduced from the sequences of peptides obtained by digestion of the globin or its cyanogen bromide fragments with trypsin, chymotrypsin, pepsin and papain. The difference in length of the beta-chain is most readily accounted for by the absence of the D helix. This small helical section is normally present in myoglobins and beta-globins but absent in alpha-chains. The deduction that it is absent from shark beta-chain is based on consideration of homology. The beta-chain shows the insertion of histidine beta2 and the deletions corresponding to residues A17 and AB1 relative to alpha-and myoglobin chains. The reactive thiol group in shark haemoglobin was shown by radioactive labelling to be residue 51 in the beta-chain, immediately preceding the E helix. The amino acid sequence of shark beta-chain shows 92 differences from human beta-chain, significantly more differences than shown by chicken or frog beta-chains, in line with its earlier time of divergence. If the tertiary structure of the shark beta-chain is the same as that of the horse then there are two changes in the alpha1beta2 contact site in oxyhaemoglobin and an additional one in deoxyhaemoglobin. When both alpha- and beta-chain contacts are considered there is a total of nine changes in residues involved in the alpha1beta2 contacts. There is no Bohr effect in shark haemoglobin, and of the residues normally involved in this effect the C-terminal histidine residue of the beta-chain is present, but the aspartyl (FG1) residue to which it is salt-linked is not, being replaced by a glutamyl residue.

Instability of DTNB-treated globin or haemoglobin

Human haemoglobin or globin in its native form reacts with 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) with uptake of two 3-carboxylato-4-nitrothiophenol groups, one for each of the reactive thiols at the beta93 positions. Attempts to isolate the DTNB-treated globin by the acetone-HC1 method, which unfolds the protein chains, result in disulphide interchange and oxidation of almost all the uncoupled "masked" thiol groups. This modification is in marked contrast to the stability of haemoglobin or globin treated with reagents such as iodoacetic acid or N-ethylmaleimide that do not form disulphide bonds in blocking the thiol groups. The derivatized globin chains have been separated by urea-thiol buffer chromatography on carboxymethycellulose columns. Amino acid analysis and peptide mapping established the presence and location of disulphide bonds, whilst gel filtration in urea buffers and sodium dodecyl sulphate acrylamide gel electrophoresis defined the size of the products.

Haemoglobin C and haemoglobin O Arab-thalassaemia in families of Greek origin

A case of Haemoglobin C trait and a family with Haemoglobin O Arab thalassaemia from Greece are described. Both Haemoglobin C and Haemoglobin O Arab were identified by peptide analysis.

Studies on monotreme proteins. VII. Amino acid sequence of myoglobin from the platypus, Ornithoryhynchus anatinus

Myoglobin isolated from skeletal muscle of the platypus contains 153 amino acid residues. The complete amino acid sequence has been determined following cleavage with cyanogen bromide and further digestion of the four fragments with trypsin, chymotrypsin, pepsin and thermolysin. Sequences of the purified peptides were determined by the dansyl-Edman procedure. The amino acid sequence showed 25 differences from human myoglobin and 24 from kangaroo myoglobin. Amino acid sequences in myoglobins are more conserved than sequences in the alpha- and beta-globin chains, and platypus myoglobin shows a similar number of variations in sequence to kangaroo myoglobin when compared with myoglobin of other species. The date of divergence of the platypus from other mammals was estimated at 102 +/- 31 million years, based on the number of amino acid differences between species and allowing for mutations during the evolutionary period. This estimate differs widely from the estimate given by similar treatment of the alpha- and beta-chain sequences and a constant rate of mutation of globin chains is not supported.

Haemoglobins of the shark, Heterodontus portusjacksoni II. Amino acid sequence of the alpha-chain

The amino acid sequence of the alpha-chain of the principal haemoglobin from the shark, H. portusjacksoni has been determined. The chain has 148 residues and is acetylated at the amino terminal. The soluble peptides obtained by tryptic and chymotryptic digestion of the protein or its cyanogen bromide fragments were isolated by gel filtration, paper ionophoresis and paper chromatography. The amino acid sequences were determined by the dansyl-Edman procedure. The insoluble "core" peptide from the tryptic digestion contained 34 residues and required cleavage by several prosteases before the sequence was established. Compared with human alpha-chain there are 88 amino acid differences including the additional seven residues which appear on the amino terminal of the shark chain. There is also one deletion and one insertion. The chain contains no tryptophan but has four cysteinyl residues which is the highest number of such residues recorded for a vertebrate globin. In the alpha1beta1 contact sites there are four changes in the oxyhaemoglobin form and six deoxy form. Nine of the 16, alpha1beta1 contact sites show variation while three of the haem contact sites have changed in comparison to the residues known to be involved in these interactions in horse haemoglobin alpha-chain. Use of the sequence data to estimate a time of divergence of the shark from the main vertebrate line yielded the value of 410 +/- 46 million years. The data, in general, support the palaeontological view that bony fishes arose before the elasmobranchs.

Studies on monotreme proteins. VI. Amino acid sequence of the beta-chain of haemoglobin from the platypus, Ornithorhynchus anatinus

The amino acid sequence of the 146 residues of the beta-chain of the major haemoglobin from the platypus has been determined. The soluble peptides derived from the chain by tryptic digestion were isolated by paper ionophoresis and chromatography. The amino acid sequences were determined by the dansyl-Edman procedure or by further digestion with other enzymes. The tryptic peptides were aligned by homology with other beta-globins. There were 14 changes in sequence compared with echidna beta-chain. The number of changes in sequence compared with human beta-chain is 34 which is less than the 39 changes between human and platypus alpha-chains. Generally there are more changes between beta-chains; there are only three other examples reported where there are more changes between alpha-chains than beta-chains, these are of echidna, rabbit and dog globins. By comparison with the 'contact sites' in horse haemoglobin there is one change in beta-haem contacts, three changes in beta1-alpha1 contacts and no changes in beta2-alpha1 contacts. The date of divergence of the monotremes from the other mammals was estimated at 132 +/- 33 million years, based on the number of amino acid differences between species and allowing for multiple mutations during the evolutionary period. This estimate differs widely from the estimate given by similar treatment of the alpha-chain sequences and the significance of this discrepancy to the validity of the method is discussed.

Studies on monotreme proteins. V. Amino acid sequence of the alpha-chain of haemoglobin from the platypus, Ornithorhynchus anatinus

Blood from the platypus contained three haemoglobins which were separated by chromatography on DEAE-Sephadex. The major component, Hb-I, was converted to globin and fractionated into the oc-and p-chains by chromatography on eM-cellulose in 8M urea-thiol buffers, and the complete amino acid sequence of the 141 residues of the oc-chain were determined. Peptides derived from the oc-chain by tryptic digestion were isolated by paper ionophoresis and chromatography. The amino acid sequences were determined by the dansyl-Edman procedure or by further digestion with other enzymes.

Haemoglobins of the shark, Heterodontus portusjacksoni

The haemoglobins of the Port Jackson shark, H. portusjacksoni, were resolved by cation-exchange chromatography of their carboxymethylated forms into two fractions, Hb-I and Hb-II, which were present in approximately equal proportions. A third, non-haem, acidic protein component, representing 5 % of the total protein, was also resolved. This protein is apparently of high molecular weight and is present in different polymorphic forms. The haemoglobins of the shark are subject to rapid aggregation, by disulphide bond formation, following lysis of the red cells. The aggregation is reversed by treatment with thiols, and prevented by combination of the two to four 'reactive' thiol groups with iodoacetate or other thiol-blocking reagents. The molecular weights of the haemoglobins are approximately 61 000, suggesting a tetrameric molecule.

Studies on monotreme proteins. IV. Amino acid sequence of haemoglobin-IA of the echidna; a comparison of major haemoglobins from two geographical groups of echidnas

The amino acid sequences of the ex-and fJ-chains from a major haemoglobin (Hb-IA) of an echidna geographically isolated from those animals previously studied have been determined. The fJ-chain of Hb-IA was identical in amino acid sequence with the fJ-chain in Hb-IB. The ex-chain of Hb-IA varied in four positions from that in Hb-IB, and had one more acidic group, in line with the higher electro-phoretic mobility of Hb-IA at pH 8� 5. There were no differences in 'contact site' residues in the ex-chains of the two haemoglobins.

Studies on monotreme proteins. 3. Amino acid sequence of the alpha- and beta-globin chains of the minor haemoglobin from the echidna, Tachyglossus aculeatus aculeatus

Echidnas exhibit polymorphism in their haemoglobins. The minor component in animals from the mainland of Australia is Hb-IIA, which can be identified by electrophoretic migration rate and separated by chromatography on DEAE-Sephadex. This minor component has IX- and fi-globin chains which were only partially separated by chromatography on carboxymethylcellulose columns. By tryptic digestion of the partially purified chains, followed by fractionation by paper ionophoresis and chromatography, the component pep tides from the IX- and fi-chains were isolated and their amino acid sequences determined.

Studies on monotreme proteins. II. Amino acid sequence of the alpha-chain in haemoglobin from the echidna, Tachyglossus aculeatus aculeatus

The amino acid sequence of the 141 residues of the IX-chain of the major haemoglobin (Hb-IB) from the echidna has been determined. The soluble peptides formed by tryptic digestion were isolated by gel filtration, paper ionophoresis, and paper chromatography.

Nucleotide sequences of similar size from the coliphage R17 genome

A sequence of 33 nucleotides from the coliphage R17 RNA genome was determined. It constitutes the main component of a mixture of fragments that migrate together on electrophoresis in a separation according to molecular weight. Fragments of comparable chain length from 3' end of RNA from coliphage R17, from a region preceding and overlapping the coat-protein cistron ribosome binding site and from the beginning of the A-protein cistron, were also found and characterized. ;Hairpin'-like secondary structures are proposed for the longer fragments, one of which appears to have a tetranucleotide excised in the loop region.

Studies on monotreme proteins. I. Amino acid sequence of the -chain of haemoglobin from the echidna, Tachyglossus aculeatus aculeatus

Blood from the echidna (or spiny anteater), T. aculeatu8 aculeatus, contained two haemoglobins which were separated by chromatography on DEAE-Sephadex. The major component, Hb-I, was converted to globin and fractionated into the ,a-and <x-chains by chromatography on carboxymethyl cellulose in 8M urea-thiol buffers.

Studies on marsupial proteins. VI. Evolutionary changes of beta-globins of the macropodidae and the amino acid sequence of beta-globin from Potorous tridactylus

Haemoglobins from 13 species of the subfamily Macropodinae and one species of the subfamily Potoroinae have been studied.

The amino acid sequence of the large plakalbumin peptide and the C-terminal sequence of ovalbumin

The amino acid sequence of a 33-residue peptide isolated from plakalbumin by gel filtration in 6M urea at pH 3 and derived from the C-terminal portion of ovalbumin has been determined. Enzyme digestion of the hydrophobic areas by thermolysin, papain, ana subtilisin BPN' gave peptides with overlapping sequences. The peptides were fractionated by a combination of paper ionophoresis and chromatography and their sequences determined by the dansyl-Edman technique.