Goldman A

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Full name : Goldman Adrian

First name : Adrian

Mail : Structural Biology and Biophysics, Institute of Biotechnology, PO Box 65, University of Helsinki, FIN-00014, Helsinki

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Country : Finland

Email : adrian.goldman@helsinki.fi

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References (6)

Title : Improving on nature's shortcomings: evolving a lipase for increased lipolytic activity, expression and thermostability - Alfaro-Chavez_2019_Protein.Eng.Des.Sel_32_13
Author(s) : Alfaro-Chavez AL , Liu JW , Porter JL , Goldman A , Ollis DL
Ref : Protein Engineering Des Sel , 32 :13 , 2019
Abstract : An enzyme must be soluble, stable, active and easy to produce to be useful in industrial applications. Not all enzymes possess these attributes. We set out to determine how many changes are required to convert an enzyme with poor properties into one that has useful properties. Lipase Lip3 from Drosophila melanogaster had been previously optimised for expression in Escherichia coli. The expression levels were good, but Lip3 was mainly insoluble with poor activity. Directed evolution was used to identify variants with enhanced activity along with improved solubility. Five variants and the wild-type (wt) enzyme were purified and characterised. The yield of the wt enzyme was just 2.2 mg/L of culture, while a variant, produced under the same conditions, gave 351 mg. The improvement of activity of the best variant was 200 times higher than that of the wt when the crude lysates were analysed using pNP-C8, but with purified protein, the improvement observed was 1.5 times higher. This means that most of the increase of activity is due to increase in solubility and stability. All the purified variants showed increased thermal stability compared with the wt enzyme that had a T1/2 of 37 degrees C, while the mutant with P291L of 42.2 degrees C and the mutant R7_47D with five mutations had a value of 52.9 degrees C, corresponding to an improvement of 16 degrees C. The improved variants had between five and nine changes compared with the wt enzyme. There were four changes that were found in all 30 final round variants for which sequences were obtained; three of these changes were found in the substrate-binding domain.
ESTHER : Alfaro-Chavez_2019_Protein.Eng.Des.Sel_32_13
PubMedSearch : Alfaro-Chavez_2019_Protein.Eng.Des.Sel_32_13
PubMedID: 31403166
Gene_locus related to this paper: drome-lip3

Title : Is the bovine lysosomal phospholipase B-like protein an amidase? - Repo_2014_Proteins_82_300
Author(s) : Repo H , Kuokkanen E , Oksanen E , Goldman A , Heikinheimo P
Ref : Proteins , 82 :300 , 2014
Abstract : The main function of lysosomal proteins is to degrade cellular macromolecules. We purified a novel lysosomal protein to homogeneity from bovine kidneys. By gene annotation, this protein is defined as a bovine phospholipase B-like protein 1 (bPLBD1) and, to better understand its biological function, we solved its structure at 1.9 A resolution. We showed that bPLBD1 has uniform noncomplex-type N-glycosylation and that it localized to the lysosome. The first step in lysosomal protein transport, the initiation of mannose-6-phosphorylation by a N-acetylglucosamine-1-phosphotransferase, requires recognition of at least two distinct lysines on the protein surface. We identified candidate lysines by analyzing the structural and sequentially conserved N-glycosylation sites and lysines in bPLBD1 and in the homologous mouse PLBD2. Our model suggests that N408 is the primarily phosphorylated glycan, and K358 a key residue for N-acetylglucosamine-1-phosphotransferase recognition. Two other lysines, K334 and K342, provide the required second site for N-acetylglucosamine-1-phosphotransferase recognition. bPLBD1 is an N-terminal nucleophile (Ntn) hydrolase. By comparison with other Ntn-hydrolases, we conclude that the acyl moiety of PLBD1 substrate must be small to fit the putative binding pocket, whereas the space for the rest of the substrate is a large open cleft. Finally, as all the known substrates of Ntn-hydrolases have amide bonds, we suggest that bPLBD1 may be an amidase or peptidase instead of lipase, explaining the difficulty in finding a good substrate for any members of the PLBD family.
ESTHER : Repo_2014_Proteins_82_300
PubMedSearch : Repo_2014_Proteins_82_300
PubMedID: 23934913

Title : Downstream coding region determinants of bacterio-opsin, muscarinic acetylcholine receptor and adrenergic receptor expression in Halobacterium salinarum - Bartus_2003_Biochim.Biophys.Acta_1610_109
Author(s) : Bartus CL , Jaakola VP , Reusch R , Valentine HH , Heikinheimo P , Levay A , Potter LT , Heimo H , Goldman A , Turner GJ
Ref : Biochimica & Biophysica Acta , 1610 :109 , 2003
Abstract : The aim of this work is to develop a prokaryotic system capable of expressing membrane-bound receptors in quantities suitable for biochemical and biophysical studies. Our strategy exploits the endogenous high-level expression of the membrane protein bacteriorhodopsin (BR) in the Archaeon Halobacterium salinarum. We attempted to express the human muscarinic acetylcholine (M(1)) and adrenergic (a2b) receptors by fusing the coding region of the m1 and a2b genes to nucleotide sequences known to direct bacterio-opsin (bop) gene transcription. The fusions included downstream modifications to produce non-native carboxyl-terminal amino acids useful for protein identification and purification. bop mRNA and BR accumulation were found to be tightly coupled and the carboxyl-terminal coding region modifications perturbed both. m1 and a2b mRNA levels were low, and accumulation was sensitive to both the extent of the bop gene fusion and the specific carboxyl-terminal coding sequence modifications included. Functional a2b adrenergic receptor expression was observed to be dependent on the downstream coding region. This work demonstrates that a critical determinant of expression resides in the downstream coding region of the wild-type bop gene and manipulation of the downstream coding region of heterologous genes may affect their potential for expression in H. salinarum.
ESTHER : Bartus_2003_Biochim.Biophys.Acta_1610_109
PubMedSearch : Bartus_2003_Biochim.Biophys.Acta_1610_109
PubMedID: 12586385

Title : Of barn owls and bankers: a lush variety of alpha\/beta hydrolases - Heikinheimo_1999_Structure.Fold.Des_7_R141
Author(s) : Heikinheimo P , Goldman A , Jeffries C , Ollis DL
Ref : Structure Fold Des , 7 :R141 , 1999
Abstract : alpha/beta Hydrolase fold proteins are an important, diverse, widespread group of enzymes not yet fully exploited by structural biologists. We describe the current state of knowledge of this family, and suggest a smaller definition of the required core and some possible future avenues of exploration.
ESTHER : Heikinheimo_1999_Structure.Fold.Des_7_R141
PubMedSearch : Heikinheimo_1999_Structure.Fold.Des_7_R141
PubMedID: 10404588

Title : The alpha\/beta hydrolase fold - Ollis_1992_Prot.Engin_5_197
Author(s) : Ollis DL , Cheah E , Cygler M , Dijkstra B , Frolow F , Franken SM , Harel M , Remington SJ , Silman I , Schrag JD , Sussman JL , Verschueren KHG , Goldman A
Ref : Protein Engineering , 5 :197 , 1992
Abstract : We have identified a new protein fold--the alpha/beta hydrolase fold--that is common to several hydrolytic enzymes of widely differing phylogenetic origin and catalytic function. The core of each enzyme is similar: an alpha/beta sheet, not barrel, of eight beta-sheets connected by alpha-helices. These enzymes have diverged from a common ancestor so as to preserve the arrangement of the catalytic residues, not the binding site. They all have a catalytic triad, the elements of which are borne on loops which are the best-conserved structural features in the fold. Only the histidine in the nucleophile-histidine-acid catalytic triad is completely conserved, with the nucleophile and acid loops accommodating more than one type of amino acid. The unique topological and sequence arrangement of the triad residues produces a catalytic triad which is, in a sense, a mirror-image of the serine protease catalytic triad. There are now four groups of enzymes which contain catalytic triads and which are related by convergent evolution towards a stable, useful active site: the eukaryotic serine proteases, the cysteine proteases, subtilisins and the alpha/beta hydrolase fold enzymes.
ESTHER : Ollis_1992_Prot.Engin_5_197
PubMedSearch : Ollis_1992_Prot.Engin_5_197
PubMedID: 1409539

Title : Atomic structure of acetylcholinesterase from Torpedo californica: a prototypic acetylcholine-binding protein - Sussman_1991_Science_253_872
Author(s) : Sussman JL , Harel M , Frolow F , Oefner C , Goldman A , Toker L , Silman I
Ref : Science , 253 :872 , 1991
Abstract : The three-dimensional structure of acetylcholinesterase from Torpedo californica electric organ has been determined by x-ray analysis to 2.8 angstrom resolution. The form crystallized is the glycolipid-anchored homodimer that was purified subsequent to solubilization with a bacterial phosphatidylinositol-specific phospholipase C. The enzyme monomer is an alpha/beta protein that contains 537 amino acids. It consists of a 12-stranded mixed beta sheet surrounded by 14 alpha helices and bears a striking resemblance to several hydrolase structures including dienelactone hydrolase, serine carboxypeptidase-II, three neutral lipases, and haloalkane dehalogenase. The active site is unusual because it contains Glu, not Asp, in the Ser-His-acid catalytic triad and because the relation of the triad to the rest of the protein approximates a mirror image of that seen in the serine proteases. Furthermore, the active site lies near the bottom of a deep and narrow gorge that reaches halfway into the protein. Modeling of acetylcholine binding to the enzyme suggests that the quaternary ammonium ion is bound not to a negatively charged "anionic" site, but rather to some of the 14 aromatic residues that line the gorge.
ESTHER : Sussman_1991_Science_253_872
PubMedSearch : Sussman_1991_Science_253_872
PubMedID: 1678899
Gene_locus related to this paper: torca-ACHE