scholarly journals Primary structure of the cytosolic β-glucosidase of guinea pig liver

1996 ◽  
Vol 319 (3) ◽  
pp. 829-837 ◽  
Author(s):  
William S HAYS ◽  
Steven A. JENISON ◽  
Takashi YAMADA ◽  
Andrzej PASTUSZYN ◽  
Robert H. GLEW

The cytosolic β-glucosidase (EC 3.2.1.21) present in the livers of mammalian species is distinguished by its broad specificity for sugars and its preference for hydrophobic aglycones. We purified the cytosolic β-glucosidase from guinea pig liver and sequenced 142 amino acid residues contained within 12 trypsin digest fragments. Using degenerate oligonucleotide primers deduced from the peptide sequences, a 622 bp cytosolic β-glucosidase cDNA was amplified by reverse-transcriptase PCR, using total guinea pig liver RNA as template. The ‘rapid amplification of cDNA ends (RACE)’ method [Frohman (1993) Methods Enzymol. 218, 340–356] was used to synthesize the remaining segments of the full-length cDNA. The complete cDNA contained 1671 nucleotides with an open reading frame coding for 469 amino acid residues. The amino acid sequence deduced from the cDNA sequence included the amino acid sequences of all 12 trypsin digest fragments derived from the purified enzyme. Amino acid sequence analysis indicates that the guinea pig liver cytosolic β-glucosidase is a Family 1 β-glycosidase and that it is most closely related to mammalian lactase-phlorizin hydrolase. These results suggest that the cytosolic β-glucosidase and lactase-phlorizin hydrolase diverged from a common evolutionary precursor.

1991 ◽  
Vol 277 (2) ◽  
pp. 469-475 ◽  
Author(s):  
R Dumas ◽  
M Lebrun ◽  
R Douce

Acetohydroxy acid reductoisomerase (AHRI), the second enzyme in the parallel isoleucine/valine-biosynthetic pathway, catalyses an unusual two-step reaction in which the substrate, either 2-acetolactate or 2-aceto-2-hydroxybutyrate, is converted via an alkyl migration and an NADPH-dependent reduction to give 2,3-dihydroxy-3-methylbutyrate or 2,3-dihydroxy-3-methylvalerate respectively. We have isolated and characterized a full-length cDNA from a lambda gt11 spinach library encoding the complete acetohydroxy acid reductoisomerase protein precursor. The 2050-nucleotide sequence contains a 1785-nucleotide open reading frame. The derived amino acid sequence indicates that the protein precursor consists of 595 amino acid residues including a presequence peptide of 72 amino acid residues. The N-terminal sequence of the first 16 amino acid residues of the purified AHRI confirms the identity of the cDNA. The derived amino acid sequence from this open reading frame shows 23% identity with the deduced amino acid sequences of the Escherichia coli and Saccharomyces cerevisiae AHRI proteins. There are two blocks of conserved amino acid residues in these three proteins. One of these is a sequence similar to the ‘fingerprint’ region of the NAD(P)H-binding site found in a large number of NAD(P)H-dependent oxidoreductases. The other, a short sequence (Lys-Xaa-Xaa-Xaa-Xaa-Xaa-Xaa-Xaa-Ser-His-Gly-Phe) containing the amino acids lysine and histidine, could well be the catalytic site of the first step of the AHRI reaction. Southern-blot analysis indicated that AHRI is encoded by a single gene per haploid genome of about 7.5 kbp containing at least four introns.


Biochemistry ◽  
1988 ◽  
Vol 27 (8) ◽  
pp. 2898-2905 ◽  
Author(s):  
Koji Ikura ◽  
Takaaki Nasu ◽  
Hiroyuki Yokota ◽  
Yoichi Tsuchiya ◽  
Ryuzo Sasaki ◽  
...  

2002 ◽  
Vol 76 (11) ◽  
pp. 5829-5834 ◽  
Author(s):  
Yoshio Mori ◽  
Mohammed Ali Borgan ◽  
Naoto Ito ◽  
Makoto Sugiyama ◽  
Nobuyuki Minamoto

ABSTRACT Avian rotavirus NSP4 glycoproteins expressed in Escherichia coli acted as enterotoxins in suckling mice, as did mammalian rotavirus NSP4 glycoproteins, despite great differences in the amino acid sequences. The enterotoxin domain of PO-13 NSP4 exists in amino acid residues 109 to 135, a region similar to that reported in SA11 NSP4.


2002 ◽  
Vol 68 (6) ◽  
pp. 2731-2736 ◽  
Author(s):  
Hirokazu Nankai ◽  
Wataru Hashimoto ◽  
Kousaku Murata

ABSTRACT When cells of Bacillus sp. strain GL1 were grown in a medium containing xanthan as a carbon source, α-mannosidase exhibiting activity toward p-nitrophenyl-α-d-mannopyranoside (pNP-α-d-Man) was produced intracellularly. The 350-kDa α-mannosidase purified from a cell extract of the bacterium was a trimer comprising three identical subunits, each with a molecular mass of 110 kDa. The enzyme hydrolyzed pNP-α-d-Man (Km = 0.49 mM) and d-mannosyl-(α-1,3)-d-glucose most efficiently at pH 7.5 to 9.0, indicating that the enzyme catalyzes the last step of the xanthan depolymerization pathway of Bacillus sp. strain GL1. The gene for α-mannosidase cloned most by using N-terminal amino acid sequence information contained an open reading frame (3,144 bp) capable of coding for a polypeptide with a molecular weight of 119,239. The deduced amino acid sequence showed homology with the amino acid sequences of α-mannosidases belonging to glycoside hydrolase family 38.


1998 ◽  
Vol 330 (1) ◽  
pp. 321-327 ◽  
Author(s):  
Norihiro AZUMA ◽  
Hee-Chan SEO ◽  
Øystein LIE ◽  
Qiang FU ◽  
M. Robert GOULD ◽  
...  

Prosaposin is the precursor of four small glycoproteins, saposins A-D, that activate lysosomal sphingolipid hydrolysis. A full-length cDNA encoding prosaposin from chicken brain was isolated by PCR. The deduced amino acid sequence predicted that, similarly to human and other mammalian species studied, chicken prosaposin contains 518 residues, including four domains that correspond to saposins A-D. There was 59% identity and 76% similarity of human and chicken prosaposin amino acid sequences. The basic three-dimensional structures of these saposins is predicted to be similar on the basis of the conservation of six cysteine residues and an N-glycosylation site. Identity of amino acid sequences was higher among saposins A, B and D than in saposin C. The predicted amino acid sequence of saposin B matched exactly that of purified chicken saposin B protein. The chicken prosaposin gene was mapped to a single locus, PSAP, in chicken linkage group E11C10 and is closely linked to the ACTA2 locus. This confirms the homology between chicken and human prosaposins and defines a new conserved segment with human chromosome 10q21-q24.


1962 ◽  
Vol 40 (1) ◽  
pp. 983-987 ◽  
Author(s):  
Felix Friedberg

Apoferritin isolated from livers of guinea pigs and characterized by a s°w,20 of 17.7 and a pI of 4.8 (in acetate buffer Γ/2 0.1) was hydrolyzed with 5.7 N HCl for 22 and 44 hours and its amino acid composition determined. The protein appears rich in dicarboxylic acids and in leucine. The content of sulphur-containing amino acids is fairly small.


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