Fragment Of Bovine Growth Hormone Research Articles

Preferred conformational state of the N-terminus section of a bovine growth hormone fragment (residues 96-133) in water is an omega loop.

The solution structure of a 38-amino-acid-residue, biologically active fragment of bovine growth hormone (bGH96-133) was investigated with a combined nuclear magnetic resonance (NMR) and computer modeling approach. With the distance geometry program DISGEO and distance constraints derived from nuclear Overhauser enhancement (NOE) experiments, it was found that residues Ser-100 to Tyr-110 circumscribe and omega-loop, a recently categorized feature of nonregular secondary protein structure.

Immunologically active zones in bovine growth hormone.

Antigenic determinant areas were detected in bovine growth hormone fragments 6--124 and 125--149, the former being predominant. Reduction and carboxymethylation of disulfide bridge 53--164 destroys the immunological reactivity of the area which is little affected by reduction and carbamoylmethylation. All the activity found in fragment 6--124 seems to be concentrated in the sequence 87--124.

Stimulation of human fibroblast protein, ribonucleic acid, and deoxyribonucleic acid synthesis by bovine growth hormone fragments.

Bovine GH and two fragments which were obtained by dissociation of a limited tryptic digest of the hormone stimulated protein, RNA, and DNA synthesis of contact-inhibited human fibroblasts. The stimulation of protein, RNA, and DNA synthesis was similar for the test substances. Maximal stimulation was noted at 10 nM. At that concentration, protein, RNA, and DNA synthesis were respectively increased 1.80, 1.42, and 1.37 times by GH; 1.93, 1.27, and 1.46 times by A-I (the larger fragment); and 1.99, 1.26, and 1.33 times by A-II (the smaller fragment). The action of GH, A-I, and A-II was similar to that of fetal calf serum, but was distinguished by the time course of stimulation and by the magnitude of the response. For example, GH, A-I, and A-II produced their earliest detectable effect at 10 h for protein synthesis, 22 h for RNA synthesis, and 26 h for DNA synthesis. On the other hand, serum stimulated protein, RNA, and DNA synthesis at 6, 10, and 16 h, respectively. These data show that human fibroblasts respond equally to GH, A-I, and A-II and suggest that there may be more than one "active site" in the GH molecule. Lastly, human fibroblasts may represent a useful system to study the actions of GH in vitro.

Studies on the common active site of growth hormone. Revision of the amino acid sequence of an active fragment of bovine growth hormone.

A fragment, A-II, isolated from a component of a tryptic digest of bovine growth hormone has growth-promoting activity in rats and metabolic activity in humans similar to human growth hormone. The amino acid sequence of this peptide has been reinvestigated and revised. The 38-amino acid peptide was cleaved with cyanogen bromide, chymotrypsin, and trypsin. The amino acid sequences were then established by Edman degradation as well as with overlapping peptides; Homology in the sequence was good between this bovine growth hormone fragment and peptides occurring in ovine growth hormone, human growth hormone, and human chorionic somatomammotropin.

The Effect of Acetic Acid on the Association and the State of the Tyrosine Residue of an Active Fragment of Bovine Growth Hormone

Self-association and the state of a tyrosine residue of the active fragment of bovine growth hormone were investigated by gel filtration and difference spectroscopy with various concentrations of acetic acid. In acetic acid solutions more concentrated than 1.5 m, the active fragment was found to exist as a monomeric form. Decrease in the concentration of acetic acid promoted self-association of the active fragment. Dimeric and trimeric forms were observed in 0.1 m acetic acid. By difference spectroscopy, the tyrosine residue in the active fragment showed a typical blue shift in 2.5 M acetic acid compared to 0.5 M acetic acid. The transition concentration, 1.25 M of acetic acid for the association-dissociation of the fragment was consistent with that for the appearance of the blue shift difference spectrum. It was concluded that a tyrosine residue in the active fragment was exposed on the surface of the fragment molecule in the monomer form and was held between the fragment molecules under conditions in wh...

The Effect of Acetic Acid on the Association and the State of the Tyrosine Residue of an Active Fragment of Bovine Growth Hormone

Self-association and the state of a tyrosine residue of the active fragment of bovine growth hormone were investigated by gel filtration and difference spectroscopy with various concentrations of acetic acid. In acetic acid solutions more concentrated than 1.5 m, the active fragment was found to exist as a monomeric form. Decrease in the concentration of acetic acid promoted self-association of the active fragment. Dimeric and trimeric forms were observed in 0.1 m acetic acid. By difference spectroscopy, the tyrosine residue in the active fragment showed a typical blue shift in 2.5 M acetic acid compared to 0.5 M acetic acid. The transition concentration, 1.25 M of acetic acid for the association-dissociation of the fragment was consistent with that for the appearance of the blue shift difference spectrum. It was concluded that a tyrosine residue in the active fragment was exposed on the surface of the fragment molecule in the monomer form and was held between the fragment molecules under conditions in which the active fragment forms dimer and trimer.

Amino Acid Sequence of a Biologically Active Fragment of Bovine Growth Hormone

Abstract The amino acid sequence of a biologically active fragment, A-II, isolated from a fraction of a tryptic digest of bovine growth hormone which has metabolic activity in humans similar to human growth hormone has been determined. The 37 amino acid peptide was cleaved with cyanogen bromide at its single methionine residue to yield two fragments. The larger fragment corresponded to the NH2-terminal and the smaller peptide (nine amino acids) to the COOH-terminal region. The sequence of 37 amino acids was established by analysis of cyanogen bromide fragments, chymotryptic and tryptic peptides. Good homology was found in the sequence between the bovine growth hormone fragment and peptides occurring in human growth hormone and human chorionic somatomammotropin. This suggests that there may be a common active site in growth hormone of various species.

ENZYMATIC MODIFICATION OF BOVINE GROWTH HORMONE BY PROTEOLYTIC STREPTOMYCETE CELL EXTRACTS.

ABSTRACT Bovine growth hormone was subjected to enzymatic hydrolysis by several crude proteolytically active streptomycete cell extracts. These digestion mixtures were fractionated on Sephadex gel columns. With each enzyme substantial amounts of hormonal aggregational products were formed during enzymatic hydrolysis with an apparent molecular weight exceeding the one for the native hormone. Fractions obtained retained various degrees of somatotrophic, lipolytic, and immunologic activities. In the course of these investigations it became apparent that the prepared bovine growth hormone fragments had a high inorganic ion binding capacity, in particular for Na+, Mg++, and SiO3−−.