Publications by authors named "Alves K"

Fertilin, a heterodimeric sperm surface protein, first identified in guinea pig, has been shown to play an important role in sperm-egg interactions. We report here the complementary DNA and deduced amino acid sequence of human fertilin beta. The human fertilin beta shares significant sequence homology with mouse, guinea pig and monkey fertilin beta and also exhibits similar structural organization.

View Article and Find Full Text PDF

The murine anti-CD18 mAb 1B4 has been humanized using CDR grafting. Three VH (Gal, Jon, and New) and two VL (Rei and Len) human frameworks, whose selection was based exclusively on their sequence identity with m1B4, were used to construct five human gamma 4/kappa recombinant antibodies: Gal/Rei, Gal/Len, Jon/Rei, and New/Rei, and a "hemichimeric" antibody pairing the VH of m1B4 with grafted Rei. Each of these h1B4 constructs completely inhibited the binding of m1B4 to activated human leukocytes with avidities (IC50) ranging from 1.

View Article and Find Full Text PDF

Two subtypes of human endothelin receptors, ETA and ETB, have been cloned and stably expressed in Chinese Hamster Ovary cells. These receptors have been characterized by [125I]-endothelin-1 binding and phosphatidyl inositol hydrolysis using the potent peptidyl ETA antagonists BQ-123 and BQ-153, as well as the potent ETB agonist, sarafotoxin S6c. In binding studies, Ki values for BQ-123 and BQ-153 are 17 nM and 13 nM for ETA compared to 11,100 nM and 7200 nM for ETB.

View Article and Find Full Text PDF

The effect of 2-naphthylamine, p-nitroaniline, o-phenanthroline, sodium deoxycholate and hydrocortisone succinate on the activity of human urine aminopeptidase, rat kidney methionyl and arginyl aminopeptidase, soybean and Enterolobium contortisiliquum seed aminopeptidase was studied using aminoacyl-2-naphthylamide and L-Leu-p-nitroanilide as substrates. Ki values ranged from 10 microM to 2.7 mM.

View Article and Find Full Text PDF

1. We have fractionated the bradykinin inactivating activity of human urine by stepwise elution chromatography on DEAE-cellulose and recovered 95% of the inactivating activity and 29% of the protein (absorbance at A280 nm). 2.

View Article and Find Full Text PDF

Urine of untreated EHP was eluted, on a ion-exchange chromatography, in two protein peaks with ACE activity, at 0.7 mS (BI) and 1.25 mS (BII), while urine of treated EHP, was eluted only in one peak with ACE activity (0.

View Article and Find Full Text PDF

Antistasin, a 15-kDa anticoagulant protein isolated from the salivary glands of the Mexican leech Haementeria officinalis, has been shown to be a potent inhibitor of factor Xa in the blood coagulation cascade. Antistasin possesses a twofold internal homology between the N- and C-terminal halves of the molecule, suggesting a gene duplication event in the evolution of the antistasin gene. This structural feature also suggests that either or both halves of the protein may possess biological activity if expressed as separate domains.

View Article and Find Full Text PDF

1. Arylamidase activity was isolated from Enterolobium contortisiliquum seeds (2 U/g) using L-Leu-2-naphthylamide as substrate to monitor the purification. 2.

View Article and Find Full Text PDF

1. Arylamidases were isolated from rat urine using L-aminoacyl-2-naphthylamides and L-Leu-p-nitroanilide as substrates to monitor the purification. 2.

View Article and Find Full Text PDF

Mlvi-1 defines a locus of proviral integration in rat thymomas induced by Moloney murine leukemia virus. pvt-1/Mis-1 represents an independently identified locus which becomes rearranged either by chromosomal translocation in murine plasmacytomas or by provirus insertion in retrovirus-induced murine and rat thymic lymphomas. Although it had been claimed that pvt-1/Mis-1 and Mlvi-1 represent two different loci, we present here evidence showing that they are identical.

View Article and Find Full Text PDF

The arylamidase activity of a soybean seed extract was measured using L-aminoacyl-2-naphthylamides and L-Leu-p-nitroanilide. The enzyme preparation was purified 42-fold with 45% yield, by precipitation with 25-75% ammonium sulfate saturation and by ion exchange and gel filtration chromatography. The highest kcat/Km ratio was that of L-Lys-2-naphthylamide (216 s-1 microM-1) and the lowest was that of L-Leu-p-nitroanilide (40 s-1 microM-1).

View Article and Find Full Text PDF

The aminopeptidase activity of rat urine was tested using L-aminoacyl-2-naphthylamides and L-Leu-p-nitroanilide. The enzyme preparation was purified by ion-exchange and gel filtration chromatography and showed only a single active protein band on 7.5% polyacrylamide gel electrophoresis.

View Article and Find Full Text PDF

An aminopeptidase from human urine (HUA) able to hydrolyze L-aminoacyl-2-naphthylamides, L-Leu-p-nitroanilide and to convert both MLBK and LBK to BK has been further purified and characterized. The preparation now obtained showed a 3-fold higher specific activity than the previously described one and a single active protein band in 7% polyacrylamide gel electrophoresis accounting for 86% of total protein. Kinetic constants for this kinin-converting enzyme were determined using L-aminoacyl-2-naphthylamides, L-Leu-p-nitroanilide and LBK.

View Article and Find Full Text PDF