scholarly journals Cloning, post-translational modifications, heterologous expression and ligand-binding of boar salivary lipocalin

2000 ◽  
Vol 350 (2) ◽  
pp. 369-379 ◽  
Author(s):  
Dietrich LOEBEL ◽  
Andrea SCALONI ◽  
Sara PAOLINI ◽  
Carlo FINI ◽  
Lino FERRARA ◽  
...  

Boar submaxillary glands produce the sex-specific salivary lipocalin (SAL), which binds steroidal sex pheromones as endogenous ligands. The cDNA encoding SAL was cloned and sequenced. From a single individual, two protein isoforms, differing in three amino acid residues, were purified and structurally characterized by a combined Edman degradation/MS approach. These experiments ascertained that the mature polypeptide is composed of 168 amino acid residues, that one of the three putative glycosylation sites is post-translationally modified and the structure of the bound glycosidic moieties. Two of the cysteine residues are paired together in a disulphide bridge, whereas the remaining two occur as free thiols. SAL bears sequence similarity to other lipocalins; on this basis, a three-dimensional model of the protein has been built. A SAL isoform was expressed in Escherichiacoli in good yields. Protein chemistry and CD experiments verified that the recombinant product shows the same redox state at the cysteine residues and that the same conformation is observed as in the natural protein, thus suggesting similar folding. Binding experiments on natural and recombinant SAL were performed with the fluorescent probe 1-aminoanthracene, which was efficiently displaced by the steroidal sex pheromone, as well as by several odorants.

1988 ◽  
Vol 251 (3) ◽  
pp. 691-699 ◽  
Author(s):  
R W Olafson ◽  
W D McCubbin ◽  
C M Kay

Biochemical and physiological studies of Synechococcus cyanobacteria have indicated the presence of a low-Mr heavy-metal-binding protein with marked similarity to eukaryotic metallothioneins (MTs). We report here the characterization of a Synechococcus prokaryotic MT isolated by gel-permeation and reverse-phase chromatography. The large number of variants of this molecule found during chromatographic separation could not be attributed to the presence of major isoproteins as assessed by amino acid analysis and amino acid sequencing of isoforms. Two of the latter were shown to have identical primary structures that differed substantially from the well-described eukaryotic MTs. In addition to six long-chain aliphatic residues, two aromatic residues were found adjacent to one another near the centre of the molecule, making this the most hydrophobic MT to be described. Other unusual features included a pair of histidine residues located in repeating Gly-His-Thr-Gly sequences near the C-terminus and a complete lack of association of hydroxylated residues with cysteine residues, as is commonly found in eukaryotes. Similarly, aside from a single lysine residue, no basic amino acid residues were found adjacent to cysteine residues in the sequence. Most importantly, sequence alignment analyses with mammalian, invertebrate and fungal MT sequences showed no statistically significant homology aside from the presence of Cys-Xaa-Cys structures common to all MTs. On the other hand, like other MTs, the prokaryotic molecule appears to be free of alpha-helical structure but has a considerable amount of beta-structure, as predicted by both c.d. measurements and the Chou & Fasman empirical relations. Considered together, these data suggested that some similarity between the metal-thiolate clusters of the prokaryote and eukaryote MTs may exist.


1996 ◽  
Vol 43 (3) ◽  
pp. 507-513 ◽  
Author(s):  
D Stachowiak ◽  
A Polanowski ◽  
G Bieniarz ◽  
T Wilusz

Two serine proteinase inhibitors (ELTI I and ELTI II) have been isolated from mature seeds of Echinocystis lobata by ammonium sulfate fractionation, methanol precipitation, ion exchange chromatography, affinity chromatography on immobilized anhydrotrypsin and HPLC. ELTI I and ELTI II consist of 33 and 29 amino-acid residues, respectively. The primary structures of these inhibitors are as follows: ELTI I KEEQRVCPRILMRCKRDSDCLAQCTCQQSGFCG ELTI II RVCPRILMRCKRDSDCLAQCTCQQSGFCG The inhibitors show sequence similarity with the squash inhibitor family. ELTI I differs from ELTI II only by the presence of the NH2-terminal tetrapeptide Lys-Glu-Glu-Gln. The association constants (Ka) of ELTI I and ELTI II with bovine-trypsin were determined to be 6.6 x 10(10) M-1, and 3.1 x 10(11) M-1, whereas the association constants of these inhibitors with cathepsin G were 1.2 x 10(7) M-1, and 1.1 x 10(7) M-1, respectively.


2020 ◽  
Vol 295 (34) ◽  
pp. 11984-11994 ◽  
Author(s):  
Jean-François Collet ◽  
Seung-Hyun Cho ◽  
Bogdan I. Iorga ◽  
Camille V. Goemans

The cell envelope of Gram-negative bacteria is a multilayered structure essential for bacterial viability; the peptidoglycan cell wall provides shape and osmotic protection to the cell, and the outer membrane serves as a permeability barrier against noxious compounds in the external environment. Assembling the envelope properly and maintaining its integrity are matters of life and death for bacteria. Our understanding of the mechanisms of envelope assembly and maintenance has increased tremendously over the past two decades. Here, we review the major achievements made during this time, giving central stage to the amino acid cysteine, one of the least abundant amino acid residues in proteins, whose unique chemical and physical properties often critically support biological processes. First, we review how cysteines contribute to envelope homeostasis by forming stabilizing disulfides in crucial bacterial assembly factors (LptD, BamA, and FtsN) and stress sensors (RcsF and NlpE). Second, we highlight the emerging role of enzymes that use cysteine residues to catalyze reactions that are necessary for proper envelope assembly, and we also explain how these enzymes are protected from oxidative inactivation. Finally, we suggest future areas of investigation, including a discussion of how cysteine residues could contribute to envelope homeostasis by functioning as redox switches. By highlighting the redox pathways that are active in the envelope of Escherichia coli, we provide a timely overview of the assembly of a cellular compartment that is the hallmark of Gram-negative bacteria.


1999 ◽  
Vol 65 (10) ◽  
pp. 4652-4658 ◽  
Author(s):  
Kohji Ohdan ◽  
Takashi Kuriki ◽  
Hiroki Kaneko ◽  
Jiro Shimada ◽  
Toshikazu Takada ◽  
...  

ABSTRACT Complete (Ba-L) and truncated (Ba-S) forms of α-amylases fromBacillus subtilis X-23 were purified, and the amino- and carboxyl-terminal amino acid sequences of Ba-L and Ba-S were determined. The amino acid sequence deduced from the nucleotide sequence of the α-amylase gene indicated that Ba-S was produced from Ba-L by truncation of the 186 amino acid residues at the carboxyl-terminal region. The results of genomic Southern analysis and Western analysis suggested that the two enzymes originated from the same α-amylase gene and that truncation of Ba-L to Ba-S occurred during the cultivation of B. subtilis X-23 cells. Although the primary structure of Ba-S was approximately 28% shorter than that of Ba-L, the two enzyme forms had the same enzymatic characteristics (molar catalytic activity, amylolytic pattern, transglycosylation ability, effect of pH on stability and activity, optimum temperature, and raw starch-binding ability), except that the thermal stability of Ba-S was higher than that of Ba-L. An analysis of the secondary structure as well as the predicted three-dimensional structure of Ba-S showed that Ba-S retained all of the necessary domains (domains A, B, and C) which were most likely to be required for functionality as α-amylase.


1996 ◽  
Vol 318 (1) ◽  
pp. 133-138 ◽  
Author(s):  
Roberto A GEREMIA ◽  
E Alejandro PETRONI ◽  
Luis IELPI ◽  
Bernard HENRISSAT

A number of genes encoding bacterial glycosyltransferases have been sequenced during the last few years, but their low sequence similarity has prevented a straightforward grouping of these enzymes into families. The sequences of several bacterial α-mannosyltransferases have been compared using current alignment algorithms as well as hydrophobic cluster analysis (HCA). These sequences show a similarity which is significant but too low to be reliably aligned using automatic alignment methods. However, a region spanning approx. 270 residues in these proteins could be aligned by HCA, and several invariant amino acid residues were identified. These features were also found in several other glycosyltransferases, as well as in proteins of unknown function present in sequence databases. This similarity most probably reflects the existence of a family of proteins with conserved structural and mechanistic features. It is argued that the present IUBMB classification of glycosyltransferases could be complemented by a classification of these enzymes based on sequence similarities analogous to that which we proposed for glycosyl hydrolases [Henrissat, B. (1991) Biochem. J. 280, 309–316].


2001 ◽  
Vol 75 (15) ◽  
pp. 7184-7187 ◽  
Author(s):  
Anne Yvon-Groussin ◽  
Pierre Mugnier ◽  
Philippe Bertin ◽  
Marc Grandadam ◽  
Henri Agut ◽  
...  

ABSTRACT Human foamy virus (HFV), a retrovirus of simian origin which occasionally infects humans, is the basis of retroviral vectors in development for gene therapy. Clinical considerations of how to treat patients developing an uncontrolled infection by either HFV or HFV-based vectors need to be raised. We determined the susceptibility of the HFV to dideoxynucleosides and found that only zidovudine was equally efficient against the replication of human immunodeficiency virus type 1 (HIV-1) and HFV. By contrast, zalcitabine (ddC), lamivudine (3TC), stavudine (d4T), and didanosine (ddI) were 3-, 3-, 30-, and 46-fold less efficient against HFV than against HIV-1, respectively. Some amino acid residues known to be involved in HIV-1 resistance to ddC, 3TC, d4T, and ddI were found at homologous positions of HFV reverse transcriptase (RT). These critical amino acids are located at the same positions in the three-dimensional structure of HIV-1 and HFV RT, suggesting that both enzymes share common patterns of inhibition.


1999 ◽  
Vol 342 (3) ◽  
pp. 721-728 ◽  
Author(s):  
Eiji ARIMITSU ◽  
Shinya AOKI ◽  
Syuhei ISHIKURA ◽  
Kumiko NAKANISHI ◽  
Kazuya MATSUURA ◽  
...  

Cynomolgus and Japanese monkey kidneys, dog and pig livers and rabbit lens contain dimeric dihydrodiol dehydrogenase (EC 1.3.1.20) associated with high carbonyl reductase activity. Here we have isolated cDNA species for the dimeric enzymes by reverse transcriptase-PCR from human intestine in addition to the above five animal tissues. The amino acid sequences deduced from the monkey, pig and dog cDNA species perfectly matched the partial sequences of peptides digested from the respective enzymes of these animal tissues, and active recombinant proteins were expressed in a bacterial system from the monkey and human cDNA species. Northern blot analysis revealed the existence of a single 1.3 kb mRNA species for the enzyme in these animal tissues. The human enzyme shared 94%, 85%, 84% and 82% amino acid identity with the enzymes of the two monkey strains (their sequences were identical), the dog, the pig and the rabbit respectively. The sequences of the primate enzymes consisted of 335 amino acid residues and lacked one amino acid compared with the other animal enzymes. In contrast with previous reports that other types of dihydrodiol dehydrogenase, carbonyl reductases and enzymes with either activity belong to the aldo-keto reductase family or the short-chain dehydrogenase/reductase family, dimeric dihydrodiol dehydrogenase showed no sequence similarity with the members of the two protein families. The dimeric enzyme aligned with low degrees of identity (14-25%) with several prokaryotic proteins, in which 47 residues are strictly or highly conserved. Thus dimeric dihydrodiol dehydrogenase has a primary structure distinct from the previously known mammalian enzymes and is suggested to constitute a novel protein family with the prokaryotic proteins.


1990 ◽  
Vol 69 (11) ◽  
pp. 1717-1723 ◽  
Author(s):  
T. Xu ◽  
E. Telser ◽  
R.F. Troxler ◽  
F.G. Oppenheim

A major macaque histatin (M-histatin 1) from the parotid secretion of the subhuman primate, Macaca fascicularis, was isolated by gel filtration on Bio-Gel P-2 and purified to homogeneity by reversed-phase high-performance liquid chromatography on a TSK-ODS C18 column. The complete amino acid sequence of M-histatin 1, determined by automated Edman degradation, is: 1 10 20 Asp-Pse-His-Glu-Glu-Arg-His-His-Gly-Arg-His-Gly-His-His-Lys-Tyr-Gly-Arg-Lys-Phe 21 30 38 His-Glu-Lys-His-His-Ser-His-Arg-Gly-Tyr-Arg-Ser-Asn-Tyr-Leu-Tyr-Asp-Asn M-histatin 1 contains 38 amino acid residues, a phosphoserine at residue 2, has a molecular weight of 4881.8, a calculated pI of 8.5, and histidine forms 26.3% of the mass. The hydropathicity plot of M-histatin 1 predicts that the molecule is entirely hydrophilic, and Chou-Fasman secondary prediction indicates that the polypeptide is devoid of alpha-helix and beta-sheet conformation in aqueous solutions but contains a series of beta turns. M-histatin 1 includes a six-amino-acid insert (residue 10-15) not present in human histatins and, with the introduction of gaps to maximize homology, it displays 89% and 91% sequence similarity with human histatins 1 and 3, respectively. M-histatin 1 exhibited fungicidal and fungistatic effects against the dimorphic pathogen, Candida albicans, in three separate bioassays. Its anticandidal effects were comparable with or greater than those of human histatins 1, 3, and 5. M-histatins 2, 3, and 4 were not sequenced directly because insufficient materials were available, but the amino acid composition of M-histatin 3 was nearly identical to that of the N-terminal 20 amino acid residues of M-histatin 1. There appears to be only one major histatin in macaque parotid secretion in contrast to the family of histatins in human parotid and submandibular secretions, and the significance of this in the context of evolution and mechanism of action in anticandidal assays is discussed.


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