[Hemoglobins, XXXVI: The primary structure of a dimeric insect hemoglobin (Erythrocruorin), component IX from Chironomus thummi thummi. Studies on the quarternary structure of the dimeric CTT-hemoglobins (author's transl)]. / Hämoglobine, XXXVI[1,2] Die Primärstruktur eines dimeren Insektenhämoglobins (ERythrocruorin) (CTT IX) (Chironomus thummi thummi. Versuche zur Quartärstruktur der dimeren CTT-Hämoglobine.

The primary structure of a dimeric insect hemoglobin (erythrocruorin), component CTT IX (Chironomus thummi thummi) was established by automatic sequence analysis. The alignment of the peptides was facilitated by producing only a few large fragments. The primary structure of CTT IX is compared with the human beta-chains and with CTT III. It is discussed, why for the dimeric CTT-hemoglobins only dimerisation can be observed but no tetramerisation. Experiments were done to locate the binding areas between the subunits in the dimeric molecule. Even after blocking of the alpha-NH2-group by cyanate, the stability of the dimeric molecule is not altered. Therefore the binding regions of the CTT-hemoglobins must be different from those of the tetrameric hemoglobins of vertebrates. Our results lead to a quarternary structure different from that of the hemoglobins of mammalians. This structure explains the possibility of dimerisation, but excludes tetramerisation.

[Hemoglobins, XXXVII. The primary structure of a monomeric insect hemoglobin (Erythrocruorin), component CTT IIIa of Chironomus thummi thummi. An anomalous Heme complex: E7 Gln, E11 Ile]. / Hmoglobine, XXXVII[1] Die Primärstruktur eines monomeren Insektenhämoglobins (Erythrocruorin), Komponente CTT IIIa von Chironomus thummi thummi. Ein ungewöhnlicher Hämkomplex: E7 Gln, E1 1 Ile.

The primary structure of the monomeric hemoglobin CTT IIIa of the midge larva of Chironomus thummi thummi is presented. Cyanogenbromide peptides and tryptic peptides were used for sequence analysis. The primary structure was established with a small number of large peptides. The complete sequencing of the cyanogen bromide peptides was enabled by the C-terminal fixation of arginine. The primary structure of CTT IIIa is compared to the beta-chains of human and to the monomeric component CTT III: CTT IIIa possesses a "tail" of 9 amino acids on the N-terminus, and shows only a small number of identical residues compared to the number that other CTT hemoglobins share with each other. Also the heme complex is unusual: E7 Gln and E11 Ile.

[Hemoglobins, XXXIV. "Hemoglobin Heide", a new embryonal hemoglobin. N-terminal sequence of the theta-chains (author's transl)]. / Hämoglobine, XXXIV. "Hämoglobin Heide", ein neues embryonales Hämoglobin N-terminale Sequenz der zeta-Ketten.

A new embryonic hemoglobin is described. Erythrocytes of pig embryos were lysed. The lysate was analyzed by gel-electrophoresis and the hemoglobins were separated on DEAE-Sephacel. The hemoglobin fractions were characterized by sequence analysis. We found in addition a new hemoglobin chain--theta-chain--not yet described. The primary structure of the theta-chains is similar to that of the epsilon-chains. There are only 3 differences in the first 30 residues. Furthermore, these theta-chains were found to be associated with theta-like chains and therefore we propose a hemoglobin of the type x2/theta 2 and we suggest the name "Hemoglobin Heide" for this new embryonic hemoglobin. In conclusion, four different globin gens (alpha-, epsilon-, theta- and theta-gens) and three different hemoglobins (Gower I, Gower II and Hb Heide) were detected in the embryonic respiration of mammals.

[The sequence of a dimeric hemoglobin (erythrocruorin), component IX, from Chironomus thummi thummi (Insecta Diptera) (author's transl)]. / Die Sequenz eines dimeren Hämoglobins (Erythrocruorin), Komponente CTT-IX von Chironomus thummi thummi (Insecta Diptera).

The primary structure of the dimeric hemoglobin (erythrocruorin) CTT-IX from the insect larva Chironomus thummi thummi (Insecta Diptera) is given. The sequence was determined automatically. The primary structure is compared with human alpha-chains.

[Hemoglobins, XXV. Hemoglobin (erythrocruorin) CTT III from Chironomus thummi thummi (Diptera). Primary structure and relationship to other heme proteins (author's transl)]. / Hämoglobine, XXV. Hämoglobin (Erythrocruorin) CTT III aus Chironomus thummi thummi (Diptera). Primärstruktur und Beziehung zu anderen Hämproteinen.

The amino acid sequence analysis of hemoglobin (erythrocruorin) CTT III from Chironomus thummi th. (Diptera) has been checked with automatic methods and completed. The protein chain consists of 136 amino acids and contains a neutral exchange isoleucine/threonine in position 57. The molecular weight of the heme protein (Thr) is 15400. The primary structure gives the chemical basis for the refinement of the X-ray structure and the understanding of the mechanism of the Bohr effect in this monomeric hemoglobin. A homologous alignment to vertebrate globins is reported. The resulting data for the phylogeny of proto-and deuterostomian animals and the function of this hemoglobin are discussed.

Ribosomal genes in Physarum polycephalum: transcribed and non-transcribed sequences have similar base compositions.

The transcribed and non-transcribed sequences in Physarum polycephalum ribosomal DNA (rDNA) were separated by restriction nuclease digestion of pure rDNA and the products fractionated by zone sedimentation in sucrose gradients. The base compositions of the fragments were determined by analytical centrifugation in CsCl or in CsCl with netropsin. All the fragments had dA + dT contents in the range 44-48%. From the known sequence arrangement and transcription pattern of Physarum rDNA it was concluded that coding sequences, transcribed but non-coding sequences, and non-transcribed sequences all possess similar base compositions, contrary to the situation in many other systems. The thermal denaturation profile of Physarum rDNA is reported. It suggests the rDNA sequence is complex and supports the above conclusion of limited heterogeneity of base composition.

The use of netropsin with CsCl gradients for the analysis of DNA and its application to restriction nuclease fragments of ribosomal DNA from Physarum polycephalum.

Netropsin binds to DNA in caesium chloride density gradients and reduces the density of the DNA. The DNA is saturated at a netropsin/DNA weight ratio of about 6 and the change in density, deltarho, at saturation is given by deltarho = -109 (dA + dT content)1.87 mg/ml for the six DNAs tested covering dA + dT contents from 0.28 to 0.69. At lower netropsin/DNA ratios the observed density shifts are consistent with a two-site model for netropsin binding to DNA. Netropsin approximately doubles the resolution of Physarum polycephalum nucleolar satellite DNA from main-band DNA. The fragments of P. polycephalum nucleolar satellite DNA obtained with the restriction endonuclease HindIII do not separate on CsCl gradients, even in the presence of netropsin, which shows that the transcribed and non-transcribed sequences in this DNA have similar nucleotide compositions.