The complete amino-acid sequence of histone H2B from the mollusc Patella granatina.

1. From the marine mollusc, Patella granatina, a histone has been isolated. Its primary structure has been established and it has been designated histone H2Bpatella. It consists of a polypeptide chain of 121 amino acids. 2. In the carboxy-terminal two thirds of the molecule there is a highly degree of sequence homology to the corresponding region in calf histone H2B with identical residues in 95% of the positions. 3. In the N-terminal 22 amino acids histone H2Bpatella differs considerably from the mammalian histone H2B and it is shorter by four residues.     

Purification of a marsupial insulin: amino-acid sequence of insulin from the eastern grey kangaroo Macropus giganteus

Insulin has been purified from kangaroo pancreas by acidic ethanol extraction, diethyl ether precipitation and gel filtration. The amino-acid sequence of this, the first marsupial insulin to be studied, is reported. It differs from human insulin by only four amino-acid substitutions, all in regions of the molecule previously known to be variable. However, it should be noted that one of these, asparagine for threonine at A8, has not been reported before. Computer comparisons of all 43 insulin sequences reported to date with kangaroo insulin show it to be most closely related to a group of mammalian insulins (dog, pig, cow, human) known to be of high biological potency. The measurement of blood glucose lowering in the rabbit by kangaroo insulin is consistent with this conclusion. Comparisons of amino-acid sequences of other proteins with their kangaroo counterparts show a greater difference, in line with the time of divergence of marsupials. The limited differences observed in insulin and cytochrome c suggest that their structures need to be closely conserved in order to maintain function.     

The amino-acid sequence of troponin C from frog skeletal muscle.

The primary structure of the troponin C from skeletal muscle of the frog Rana esculenta has been determined. The amino acid sequence was deduced from amino acid determinations of peptides obtained after cleavage with cyanogen bromide. Overlapping peptides were isolated from tryptic digests of performic-acid-oxidized troponin C and phthalylated performic-acid-oxidized troponin C. All overlaps have been determined except for the Arg-Ile sequence at position 103--104, which has been obtained by comparison with homologous troponins C. Frog troponin C consists of one polypeptide chain containing 152 amino acids. The calculated molecular weight is 18299. There is a single cysteine residue at position 101 and a single tyrosine residue at position 112. No histidine or tryptophan residues are present. The amino-terminal amino acid is N-acetylated. The homology of frog troponin C with other skeletal and cardiac troponin C is briefly discussed.     

The covalent structure of collagen. The amino-acid sequence of alpha2-CB4 from calf-skin collagen.

Sequencing of chymotrypsin, trypsin, collagenase- and hydroxylamine-derived peptides, using the automated Edman degradation procedure, yielded the complete amino acid sequence of alpha2-CB4 from calf skin collagen (321 residues). Together with the data from earlier work, an uninterrupted sequence in the helical region of the alpha2-chain from residues 1-393 is now known. Glycine is found in every third position of the peptide. Hydroxylation of proline and lysine occurs only in the Y-position of the triplet Gly-X-Y and is not complete in every position. Some residues, such as glutamic acid, leucine, phenylalanine and arginine, are distributed non-randomly between the X and Y-positions and this non-random distribution is different in the alpha1 and alpha2-chains. Comparison of the N-terminal 393 residues from the helical region of the alpha1 and alpha2-chains revealed a nearly identical distribution of charged polar residues arginine, lysine, glutamic and aspartic acids. The distribution of the triplet Gly-Pro-Hyp is simialr in both chains. The remaining residues in the alpha2-chain exhibit a high degree of substitutions when compared with those in the alpha1-chain. Approximately one in every two residues in both the X and Y-positions are substituted.     

The major protamine from stallion sperm. Isolation and amino-acid sequence

The major stallion protamine was isolated from sperm cell nuclei by extraction with 6M guanidine/5% mercaptoethanol, alkylation with 4-vinylpyridine and subsequent reversed-phase high-performance liquid chromatography. The primary structure of stallion protamine was determined by N-terminal sequencing of the intact protein and of the fragments obtained from thermolysin cleavage of the S-pyridylethylated and from endoproteinase Lys-C cleavage of the S-aminoethylated protein. Stallion protamine consists of 49 amino-acid residues and shows 49% identity with all other sequenced mammalian type 1 protamines.     

Porcine follitropin. The amino-acid sequence of the beta subunit

By treatment with tRNA in the presence of 1 mM MgCl2, a chromatin preparation was obtained containing all five major histone fractions but lacking a considerable portion of non-histone proteins. This chromatin preparation as well as chromatin extracted with 0.6 M NaCl (depleted of H1 histone and some non-histone proteins) were characterized in respect of solubility and chromatin DNA accessibility. Both samples possessed practically the same solubility in the presence of 0.15 M NaCl and 1 mM MgCl2. The solubility of tRNA-treated chromatin in 5 and 10 mM MgCl2 was higher than that of salt-extracted chromation. The accessibility of the DNA of these chromatin preparations was tested with DNA-dependent RNA polymerase of Escherichia coli as a probe, using procedure that permits measurement of binding site frequency. Both tRNA-treated and salt-extracted chromatin contained as many as 33% and untreated chromatin as few as 4% of the number of binding sites found on protein-free DNA. These results demonstrate that at least in part the non-histone proteins are responsible for salt-induced insolubility and low DNA accessibility of chromatin, thus revealing the importance of non-histone proteins in the maintenance of an overall chromatin structure.     

The amino-acid sequence of the trypsin-released inhibitor from sheep inter-alpha-trypsin inhibitor

The amino-acid sequence of the inhibitory part of the sheep serum inter-alpha-trypsin inhibitor (ITI) was determined. The inhibitor is composed of two covalently linked Kunitz-type domains. The reactive site of the C-terminal antitryptic domain contains arginine in position 71 (P1) and glycine in position 73 (P'2), whereas ITI derived inhibitors hitherto investigated contain phenylalanine in these positions. The reactive site of the N-terminal elastase inhibiting domain contains leucine in position 15 (P1) and methionine in position 17 (P'2), as in ITI-derived inhibitors of pig and horse.     

The complete amino-acid sequence of C-phycoerythrin from the cyanobacterium Fremyella diplosiphon

The amino-acid sequences of both subunits of C-phycoerythrin from the cyanobacterium Fremyella diplosiphon have been determined. The alpha-subunit contains 164 amino acid residues, two phycoerythrobilin (PEB) chromophores and has a molecular mass of 18,368 Da (protein: 17,192 Da + 2 PEB, one PEB accounting for 588 Da). The beta-subunit consists of 184 residues, three PEB chromophores and has a molecular mass of 20,931 Da (protein: 19,168 Da and 3 PEB: 1,764 Da). The five PEB chromophores (open chain tetrapyrroles) are covalently bound to six cysteine residues (one of them doubly bound to two cysteine residues). On the alpha-subunit, the first chromophore was found at position 84, homologous to the chromophore binding site of the other biliproteins APC, PC and PEC. The second chromophore, unique for the alpha-subunit of PE, is inserted together with a pentapeptide at position 143 a. On the beta-subunit, a doubly bound chromophore is attached to cysteine residues 50 and 61, similar to the rhodophytan phycoerythrins (B-PE and R-PE). The second and third chromophores were found at positions 84 and 155, homologous to the other biliproteins. A unique peptide insertion of 14 amino acid residues (without chromophore) was found at position 141 a-o in the beta-subunit and probably is located in the three-dimensional model near the additional chromophores of the C-PE alpha- and beta-subunits. Both additional chromophores of the C-PE alpha- and beta-subunit may be located at the periphery of the C-PE-trimer. The amino-acid sequence homology between C-PE alpha- and beta-subunit is 26% and to the alpha- and beta-subunits of C-PC from Mastigocladus laminosus 49% and 48%, respectively.     

The complete amino-acid sequence of the heavy chain of the human myeloma protein WIE, an immunoglobulin D.

The human myeloma protein WIE is a lambda-type immunoglobulin D; the amino-acid sequence of its Fc part and aminoethylated heavy chain was completely determined. The VH-part (subgroup III) begins N-terminally with 5-oxoproline, and it contains a long, unique CDR3 region. Since the constant part differs from known delta chains by one amino-acid substitution in the hinge region, IgD WIE probably represents an allotypic variant. As in other protein delta chains, O-glycosylations are confined to the hinge region. Furthermore, the ratios of N-glycosylations at the three positions are identical in IgD WAH [Takahashi, N. et al. (1984) J. Chromatogr. 317, 11-26.] and IgD WIE (100%, 50%, 100%). From the most conserved constant domain, C delta 3, a three-dimensional model was constructed to clarify the role of its delta-specific substitutions and glycosylation.