Human skeletal muscle proteins. The primary structure of troponin C

The primary structure of the major component of human skeletal muscle troponin C has been established. The troponin C was purified by ammonium sulphate and isoelectric fractionation, followed by two chromatographic steps on DEAE Sephadex. The sequence was determined from the different overlapping enzymic peptides and by dansyl-Edman degradation. The only difference between rabbit skeletal muscle troponin C and the major component of human skeletal troponin C was found at position 112: Ala (rabbit), Pro (human). The partial amino acid sequence of the first 86 residues of the minor component of human skeletal troponin C was found to resemble the troponin C from bovine cardiac muscle. The only difference between them, has tentatively been located at position 62: Glu (human), Asp (bovine). These similarities suggest that troponin C is, from the point of view of molecular, one of the most conservative proteins so far studied.

The gamma chain of the lamb

The sequence of the gamma-chain of lamb (Finn-Marino) haemoglobin has been investigated. Total amino acid analysis and analysis of the products of cyanylation, together with analysis of tryptic, peptic, thermolysin and Staphylococcus aureus (strain V8) protease peptides and with dansyl-Edman degradation enabled almost the entire sequence to be elucidated. The differences between this sequence and that of the gamma-chains of man, cattle, goat and Rambouillet sheep are discussed.

The occurrence of Hb E Saskatoon in Scotland

The finding of several examples of Hb E Saskatoon in the Orkney Islands, in Edinburgh and in individuals of Scottish descent in Canada but nowhere else, suggests that the original mutation occurred in Scotland, perhaps in the Orkneys.

[Serological hepatitis B characteristics in clinical laboratory control sera]

99 samples of 29 different reference sera were tested for HBs-antigen and anti-HBs radioimmunologically and by means of counter-current electrophoresis. 4 of 99 (4%) of the samples and 4 of 29 (14%) of the reference sera were HBs-antigen positive. 45 of 99 (45%) of the samples and 5 of 29 (17%) of the reference sera were anti-HBs positive. Reference sera are an additional risk for hepatitis in clinical laboratories and must be considered potentially infectious.

The myoglobin of the Cape hunting dog (Lycaon pictus)

Tryptic and other peptides from the myoglobin of the Cape hunting dog (Lycaon pictus) have been aligned with the sequence of the myoglobin of the domestic dog. One amino acid difference was found which was confirmed by dansyl-Edman degradation. The five carnivore myoglobins now known have been integrated into an evolutionary cladogram, trying to trace the pathways of mutations, and a possible ancestral myoglobin for the carnivores has been constructed.

The myoglobin of primates. VIII. Nycticebus coucang (slow loris)

To the analysis of three prosimian myoglobins reported previously [1, 2] that of the slow loris (Nycticebus coucang) has been added. A cladogram has been constructed utilising the new information to arrive at a possible ancestral prosimian myoglobin. Within the primates only the four prosimians share residues of threonine at position 34 and of isoleucine at position 142. During tryptic digestion of the loris myoglobin, some hydrolysis was observed at bonds not usually considered to be susceptible to the action of this enzyme: 52 Pro-53 Asp, and 120 Pro-121 Gly.

[Efficacy of lidoflazine in angina pectoris. A long-term double-blind study]

The long-term efficacy of lidoflazine was investigated in 40 patients with a longer history of angina pectoris and well-documented ischemic heart disease over a whole range of 18 months in double-blind technique. Significant improvement occurs to frequency and severity of angina pectoris, related to reduction in consumption of nitro-compounds and in the extent of ST-segmental depression under resting and cycloergometric test conditions. Increase in cardiac work capacity is evident. There are no changes in heart rate, blood pressure and AV-interval in the ECG. The mode of action of lidoflazine may be an increase in the formation of coronary collaterals, whereas its acute vasodilating properties, experimentally verified in the dog, does not play any important part in the treatment of human coronary insufficiency. The introduction of lidoflazine in the treatment of coronary heart disease appears to be justified as an additive medication.

Is haemoglobin G alpha Philadelphia linked to alpha-thalassaemia?

The question, "Is Hb G alpha Philadelphia linked to alpha-thalassaemia?" was first posed because the abnormal haemoglobin is found in heterozygotes at a concentration greater than 25%, the proportion predicted from a 4 alpha-chain gene model. Globin chain biosynthesis was studied in a West Indian family in which one parent had beta + thalassaemia and the other was heterozygous for the G alpha Philadelphia chain gene. The former had a globin chain production ratio alpha/beta well above 1, while the latter had a ratio significantly less than 1. One child of the marriage had inherited the beta + thalassaemia from one parent and the G alpha Philadelphia chain gene from the other and showed the typical picture of alpha/beta-thalassaemia (alpha/beta ratio slightly above normal). It is explained in the discussion that the evidence favours a close linkage of 2 alpha-chain genes.

Hemoglobin Riyadh--alpha2beta2 (120(GH3)Lys replaced by Asn). A new variant found in association with alpha-thalassemia and iron deficiency

On a field trip toSaudi Arabia (M.A.F.E.H.) in which the relationship between alpha-thalassemia and iron deficiency was studied, a fast moving hemoglobin variant was noted in a 30 year old Saudi Arabian woman. Analysis of the hemoglobin variant showed that the amino acid substitution was beta120 Lys replaced by Asn. This variant had not been described previously and has been named Hb Riyadh. There was also present an alpha-thalassemia and details are given of the imbalance of globin chain synthesis. It was possible to improve considerably the balance in vitro by the addition of hemin.

Residues 124 and 125 (H2 and H3) of the human haemoglobin delta-chain

Residues 124 and 125 of the beta-chain of human haemoglobin are prolyl-prolyl. In the delta-chain, one of these positions is occupied by a glutaminyl, and there has been uncertainty as to which of the two residues is the prolyl and which the glutaminyl. The sequence has now been established to be delta124 Pro - 125 Gln.

A drug-induced haemolytic anaemia due to Hb Torino (alpha43(CD1)Phe replaced by Val). second finding in an Italian family

The unstable haemoglobin, Tb Torino (alpha43(CD1)Phe replaced by Val), has been found for the second time in a family from the Treviso region of Italy. The haemoglobin has a slightly lower oxygen affinity than normal. In both cases, the abnormal haemoglobin is associated with inclusion body anaemia but the course of the disorder in the present case is much less severe than that previously reported. The oxygen affinity of the haemolysate has been measured and been found lower than normal.

[Post-transfusional hepatitis as a complication of surgery using the heart-lung-machine in childhood]

After open-heart surgery with extracorporeal circulation on 41 children with congenital heart disease in 13 (about 32%) a hepatitis with a long incubation period developed. In 6 out of 13 children (46%) HBS-Ag and in 2 additional ones anti-HBS could be detected. In 6 of 13 cases (46%) a chronic hepatitis ensued, which could be proved histologically in 4 cases.