Four derivatives of pepstatin, each which contains the unusual amino acid 4-amino-3-hydroxy-6methylheptanoic (statine) have been prepared.All four are potent porcine pepsin inhibitors.Both N-acetylstatine and N-acetyl-alanyl-statine competitive inhibitors for with K, values 1.2 x lo-* M 5.65 10d6 M, respectively.The value N-acetyl-valyl-statine is 4.8 10e6 M.These statyl derivatives, therefore, very strong inhibitors.The N-acetyl-statine 600-fold smaller than that its structural analog...

As the culmination of several years experiments, we propose a complete amino-acid sequence for porcine pepsin, an enzyme containing 327 residues in single polypeptide chain. In determination, was treated with cyanogen bromide. Five resulting fragments were purified. The four accounted 290 residues. Because structure 37-residue carboxyl-terminal fragment already known, it not studied. alignment these determined from methionyl-peptides had previously reported. We also discovered locations...

Human immunodeficiency virus type 1 (HIV-1) protease optimally catalyzes in the pH range of 4-6 contrast to nearly all other eukaryotic aspartic proteases, which catalyze best 2-4.A possible structural reason for higher optimal HIV-1 is absence a hydrogen bond carboxyl group active-site Asp", universally present others.To investigate this hypothesis, we have mutated residue 28 from alanine serine.Both wild-type and mutant A28S enzymes been overexpressed Escherichia coli using chemically...

Six cathepsin D isozymes have been purified from porcine spleen using a large scale purification procedure. Five isozymes, I to V, an identical molecular weight of 50,000 and are similar in specific activity. Isozymes IV contained two polypeptide chains each. The light heavy Mr = 15,000 35,000, respectively. Isozyme V is single polypeptide. the sixth isozyme about 100,000 it has only 5% activity other isozymes. On Ouchterlony immunodiffusion, antiserum formed precipitin lines against...

The complete amino acid sequence of porcine pepsin (EC 3.4.4.1) was constructed from the five cyanogen bromide fragments.The one these fragments, CBBA, is reported here.The sequences 4 other fragments are known previous work.Porcine contains 327 residues with three structural variants.The active center aspartyl residue, which reacts 1,2-epoxy-3-(p-nitrophenoxy)propane (Chen, K.

Intramolecular pepsinogen activation is inhibited either by pepstatin, a potent pepsin inhibitor, or purified globin from hemoglobin, good substrate. Also, at pH 2 can be bound to pepstatin-Sepharose column and recovered as native zymogen upon elution in 8 buffer. Kinetic studies of the inhibition show that binds intermediate. This interaction gives rise competitive intramolecular activation. The evidence presented this paper suggests converted rapidly acidification intermediate delta. In...

1. The amino acid sequences around three disulphide bridges and four methionine residues of porcine pepsin were studied by using diagonal electrophoresis methods. 2. Two the in small loops five six residues. sequence one two half-cystine third bridge had a large number acidic 3. tetrapeptide containing phosphoserine was also determined. 4. Four unique methionine-containing constructed. information is sufficient for determination overlaps cyanogen bromide fragments pepsin. 5. usefulness...

Two 13-residue glycopeptides were isolated from the digestion of purified porcine spleen cathepsin B by Staphylococcus aureus protease using high performance liquid chromatography.The major peptide, which is about 73% total, had amino acid sequence His-His-Val-Asn(CH20)-Gly-Ser-Arg-Pro-Pro-Cys-Thr-Gly-Glu.This peptide contains only a single Nacetylglucosamine residue linked to asparagine at fourth @-linkage.The minor replacement in otherwise identical that peptide.A serine was found 10...

The major cathepsin B isozyme CB-I purified from porcine spleens was studied for its specificity against various peptide and denatured protein substrates. enzyme degraded all the substrates by an exopeptidase activity. were mainly a dipeptidyl carboxypeptidase activity of except angiotensin I, which COOH-terminal leucine residue released. failed to hydrolyze peptides having proline or cysteic acid in COOH-terminal, penultimate, antepenultimate positions. Reduced carboxymethylated soybean...

The complete amino acid sequence of an aspartic protease from Rhizopus chinensis, rhizopuspepsin isozyme PI 5, has been determined.Partial sequences were first obtained the isolated by a combination chemical and proteolytic enzyme cleavages, peptide purifications, Edman degradations.About one-half was revealed this approach.To sequence, cDNA library R. chinensis in pBR322 constructed.An oligonucleotide probe synthesized based on Trp-Trp-Gly-Ile-Thr, about 40 positive clones identified colony...

Our previous studies on carbohydrate structures of purified porcine spleen cathepsin B indicated that there are two isozymes, each containing a different (Takahashi, T., Schmidt, P.G., and Tang, J. (1984) Biol. Chem. 259, 6059-6062). We have now isolated these enzymes carried out comparative study their enzymic properties. The major isozyme (CB-I) is two-chain enzyme (Mr = 28,000) with light chain 5,000) heavy 23,000), whereas the minor (CB-II) single 27,000). NH2-terminal amino acid...

Streptokinase (SK) is a thrombolytic agent widely used for the clinical treatment of clotting disorders such as heart attack. The based on ability SK to bind plasminogen (Pg) or plasmin (Pm), forming complexes that proteolytically activate other Pg molecules Pm, which carries out fibrinolysis. contains three major domains. N-terminal domain, SKα, provides complex with substrate recognition towards Pg. SKα unique mobile loop, residues 45–70, absent in corresponding domains bacterial...

In order to study the relationships of aspartic proteases, we have modified pepsin, a single-chain eukaryotic enzyme, two-chain heterodimer, which resembles proteases from retrovirus, including human immunodeficiency virus. Two fragments pepsinogen, residues 1P-172 and 173-326, were expressed separately in Escherichia coli. Mixtures chains refolded urea solutions generate an active was converted pepsin acid solutions. The intramolecular bimolecular activation constants (k1 k2) pepsinogen are...

The primary genetic defect in the lysosomal storage disease mucolipidosis III (ML III) is enzyme uridine diphospho-N-acetylglucosamine:lysosomal N-acetylglucosamine-1-phosphotransferase. This has two well-defined functions: specific recognition of enzymes (recognition function) and phosphorylation their oligosaccharides (catalytic function). Using fibroblasts from patients with ML as source enzyme, alpha-methylmannoside substrates, we have identified defects both these functions. In one...

The present study was a case on the application of Content and Language Integrated Learning (CLIL) for an Artificial Intelligence (AI) English reading course in Chinese general education (GEE) context. It aimed to investigate effectiveness CLIL improving EFL learners’ AI knowledge. significant practice applying China provided some recommendations teaching English. This proposed two research questions: 1. What are effects students’ knowledge?; 2. How do students perceive CLIL? An conducted as...

The protease of human immunodeficiency virus (HIV) has been extensively studied. structure and function relationships this its role in HIV life cycle is well known. We have use recombinant mutagenesis technology to study compare it the eukaryotic aspartic proteases. When putative active-site hydrogen bonds are placed protease, pKa values two groups only slightly downshifted. Corresponding removal these H-bonds from active sites pepsin rhizopuspepsin do not appreciably alter values. kcat...

Abstract This paper discusses the development of school soccer with help artificial intelligence. Propose a machine learning-based action feature extraction method for students in soccer. Obtain images playing and identify actions based on threshold recognition algorithm. The Harris 3D operator is used to establish potential function sequence, AdaBoost algorithm filter data soccer, which as training sample realize To extract effective values improve accuracy algorithm, model SVM was...