Genetic study of pancreatic proteinase in mice (Mus musculus): Genetic variants of trypsin and chymotrypsin

Three to five isozymes of pancreatic proteinase exist in mice, and they have been designated as bands I, II, III, IV, and V. Identification experiments of these isozymes were carried out in this study; banks I, IV, and V are trypsin, and bands II and III are chymotrypsin. Therefore, it is concluded that Prt-1, controlling band V, is a locus for trypsin and Prt-2, controlling bands II and III, is a locus for chymotrypsin. In addition, a new locus, Prt-3, has been found. At this locus the two allelic genes, Prt-3 ^a and Prt-3 ^b , control the low and high tryptic activities of band IV, respectively. Prt-3 is present only in the strain Mol-A. Linkage experimentation has shown that Prt-1 is closely linked to Prt-3.     

Genetic study of pancreatic proteinase and α-amylase in mice (Mus musculus)

Genetic variants were found at two loci for pancreatic proteinase in mice. The Prt-1 locus contains a pair of allelic genes, Prt-1 ^a and Prt-1 ^b , ad the Prt-2 locus contains two codominant allelic genes, Prt-2 ^a and Prt-2 ^b .Expression of the two genetic variants of proteinase allowed mice strains used in this study to be classified into three phenotypic classes. Prt-1 ^b andPrt-2 ^a were found in most of the Japanese inbred strains, Prt-1 ^b andPrt-2 ^a were found in most of the inbred strains imported from the United States, and, furthermore, Prt-1 ^b and Prt-2 ^b were present in Japanese feral-origin mice strains. Prt-1, Prt-2, and Amy-2 loci did not belong to the same linkage group.     

Evolutionary relationships between laboratory mice and subspecies of Mus musculus based on the genetic study of pancreatic proteinase loci,Prt-1, Prt-2, Prt-3, and Prt-6

Various patterns of mouse pancreatic proteinase activity bands were observed on agarose gel electrophoresis. Prt-1 ^a and Prt-1 ^b genes control the positive (PRT-1A) and negative (PRT-1B) expression of tryptic band V, respectively; Prt-2 ^a and Prt-2 ^b correspond to chymotryptic bands II (PRT-2A) and III (PRT-2B); Prt-3 ^a and Prt-3 ^b control the low (PRT-3A) and high (PRT-3B) tryptic activities of band IV; the Prt-1 and Prt-3 loci are closely linked on the same chromosome; Prt-6 ^a and Prt-6 ^b correspond to tryptic bands I (PRT-6A) and I (PRT-6B). Twenty-four laboratory strains from the United States showed the phenotype PRT-1A, PRT-3A, and PRT-2A. Of laboratory strains established in Europe, 6 showed PRT-1A, PRT-3A, and PRT-2A, and 10 had PRT-1B, PRT-3A, and PRT-2A bands. Most wild mice around the world and their descendants showed the phenotype PRT-1B, PRT-3B, and PRT-2A. Only the phenotype of M. m. brevirostris was PRT-1A, PRT-3A, and PRT-2A, which was the same as most laboratory inbred strains. PRT-2B was observed mainly in Japanese (M. m. molossinus) and Korean (M. m. yamashinai) wild mice. PRT-6B was detected only in Mus spicilegus and Mus caroli, but all other mice including wild populations and laboratory strains showed PRT-6A. New biochemical phenotypes such as PRT-2C and PRT-3C were also found in this study.     

Linkage between low-density lipoprotein and igk light-chain genes in rabbits

The rabbit geneLpq, which codes for a low-density serum lipoprotein², is linked (34.6 ± 5.3 centimorgans) to the Ig kappa light-chain gene (Ab). There is no evidence thatLpq is linked to another gene,Prt, that was previously found to be linked to theAb gene. This suggests that the gene order for the three genes isPrt- Ab- Lpq. Abbreviations used in this paper Ig immunoglobulin - a the heavy-chain variable-region geneAa - b the kappa light-chain geneAb - q the low-density serum lipoprotein geneLpq     

Characterization of midgut proteinase activities of white grubs: Lepidiota noxia,Lepidiota negatoria,and Antitrogus consanguineus (scarabaeidae,melolonthini)

The proteinases in the midguts of three scarab white grub species, Lepidiota noxia, L. negatoria, and Antitrogus consanguineus, were investigated to classify the proteinases present and to determine the most effective proteinase inhibitor for potential use as an insect control agent. pH activity profiles indicated the presence of serine proteinases and the absence of cysteine proteinases. This was confirmed by the lack of inhibition by specific cysteine proteinase inhibitors. Trypsin, chymotrypsin, elastase, and leucine aminopeptidase activities were detected by using specific synthetic substrates. A screen of 32 proteinase inhibitors produced 9 inhibitors of trypsin, chymotrypsin, and elastase which reduced proteolytic activity by greater than 75%. © 1995 Wiley-Liss, Inc.     

Purification and characterization of a proteinase inhibitor from field bean, Dolichos lablab perpureus L

A proteinase inhibitor resembling Bowman-Birk family inhibitors has been purified from the seeds of cultivar HA-3 of Dolichos lablab perpureus L. The protein was apparently homogeneous as judged by SDS–PAGE, PAGE, IEF, and immunodiffusion. The inhibitor had 12 mole% 1/2-cystine and a few aromatic amino acids, and lacks tryptophan. Field bean proteinase inhibitor (FBPI) exhibited a pI of 4.3 and an M _r of 18,500 Da. CD spectral studies showed random coiled secondary structure. Conformational changes were detected in the FBPI–trypsin/chymotrypsin complexes by difference spectral studies. Apparent K _a values of complexes of inhibitor with trypsin and chymotrypsin were 2.1 × 10⁷ M^–1 and 3.1 × 10⁷ M^–1, respectively. The binary and ternary complexes of FBPI with trypsin and chymotrypsin have been isolated indicating 1:1 stoichiometry with independent sites for cognate enzymes. Amino acid modification studies showed lysine and tyrosine at the reactive sites of FBPI for trypsin and chymotrypsin, respectively.     

Studies on Proteinases from Gliocladium roseum

The alkaline proteinases of Gliocladium roseum (Link) Bainier were purified in crystalline forms by procedures of alcoholic precipitation, fuller’s earth- and acrinol-treatment, and isolated in two types. (Proteinases I and II). Both of these proteinases were homogeneous on zone electrophoresis with polyacrylamide gel (Gyanogum 41), and had the optimal pH values of 11 (Proteinase I) and 10 (Proteinase II), and the optimal temperature of 45°C.

The enzymatic reaction of proteinase I was remarkably promoted by Fe⁺⁺ and Co⁺⁺, and that of proteinase II was promoted by Fe⁺⁺, Go⁺⁺ and Ca⁺⁺, and both proteinases were protected from heat-inactivation by Ca⁺⁺ Proteinase II was activated remarkably by Cl^? under the existence of Fe⁺⁺, but proteinase I was unaffected by the anion.

The order of strength of proteolytic power of these proteinases and chymotrypsin on casein was as follows; proteinase I> proteinase II> chymotrypsin.     

Substrate specificity of carboxyl proteinase fromPycnoporus coccineus,a wood-deteriorating fungus

A carboxyl proteinase was purified from submerged-culture filtrate of a wood-deteriorating basidiomycete,Pycnoporus coccineus. The purified enzyme was found to be essentially homogeneous in disc gel electrophoresis tests at pH 9.4 and 2.3. The specificity and mode of action ofP. coccineus carboxyl proteinase I_a were investigated with the oxidized B-chain of insulinP. coccineus carboxyl proteinase I_a hydrolyzed primarily three peptide bonds, Ala¹⁴-Leu¹⁵, Tyr¹⁶-Leu¹⁷, and Phe²⁴-Phe²⁵ bonds, in the oxidized B-chain of insulin.     

Heterochromatin differentiation and phylogenetic relationship of the A genomes in diploid and polyploid wheats

Summary Heterochromatin differentiation, including band size, sites, and Giemsa staining intensity, was analyzed by the HKG (HCl-KOH-Giemsa) banding technique in the A genomes of 21 diploid (Triticum urartu, T. boeoticum and T. monococcum), 13 tetraploid (T. araraticum, T. timopheevi, T. dicoccoides and T. turgidum var. Dicoccon, Polonicum), and 7 cultivars of hexaploid (T. aestivum) wheats from different germplasm collections. Among wild and cultivated diploid taxa, heterochromatin was located mainly at centromeric regions, but the size and staining intensity were distinct and some accessions' genomes had interstitial and telomeric bands. Among wild and cultivated polyploid wheats, heterochromatin exhibited bifurcated differentiation. Heterochromatinization occurred in chromosomes 4A^t and 7A^t and in smaller amounts in 2A^t, 3A^t, 5A^t, and 6A^t within the genomes of the tetraploid Timopheevi group (T. araraticum, and T. timopheevi) and vice versa within those of the Emmer group (T. dicoccoides and T. turgidum). Similar divergence patterns occurred among chromosome 4A^a and 7A^a of cultivars of hexaploid wheat (T. aestivum). These dynamic processes could be related to geographic distribution and to natural and artifical selection. Comparison of the A genomes of diploid wheats with those of polyploid wheats shows that the A genomes in existing diploid wheats could not be the direct donors of those in polyploid wheats, but that the extant taxa of diploids and polyploids probably have a common origin and share a common A-genomelike ancestor.Contribution of the College of Agricultural Sciences, Texas Tech Univ. Journal No. T-4-233.     

The Preparation of Trypsins and Chymotrypsins From Bovine and Porcine Residues After Insulin Extraction

Bovine and porcine pancreatic residue, remaining after the extraction of insulin, has been used to prepare a proteinase powder. This powder was used as a source of trypsin and chymo-trypsin. The individual enzymes were isolated and purified by chromatography on sulfopropyl (SP)-Sephadex C-25 and affinity chromatography on soybean trypsin inhibitor (STI)-Sepharose. The bovine proteinase powder contained a-chymotrypsin, trypsin and chymotrypsin B in the ratio 5:2:1. The porcine powder contained cationic trypsin, anionic trypsin and cationic chymotrypsin in the ratio 5 : 1. 4 : 3. The isolated enzymes were characterized and found to be identical with enzymes isolated from fresh tissue with the exception of porcine chymotrypsin. Porcine cationic chymotrypsin was isolated as two distinct forms, A-l and A-2, which appear to be different activation products of porcine chymotrypsinogen A. Both forms resemble bovine a-chymotrypsin, a three chain structure, rather than porcine chymo-trypsin A, a two chain structure. Furthermore, the B-chain appears to be cleaved, possibly at residues Phe₈₉-Lys₉₀.     

Structural difference of chymotrypsinogens forming chymotrypsin variants in Japanese quail

A chymotrypsinogen showing the phenotype AA of chymotrypsin was purified from quail pancreas, and its chromatographic behavior, molecular weight, and electrophoretic mobility were very similar to those of another chymotrypsinogen, showing the aa phenotype of chymotrypsin. However, after activation, this chymotrypsinogen from AA showed band 5 of chymotrypsin, while the other chymotrypsinogen from aa did not. Peptide mapping demonstrated that the molecular structures of the two chymotrypsinogens are different. It was recognized that chymotrypsin variants result from activated products of different molecular structures of chymotrypsinogens.     

Inhibition of endogenous trypsin- and chymotrypsin-like activities in transgenic lettuce expressing heterogeneous proteinase inhibitor SaPIN2a

SaPIN2a, a proteinase inhibitor II from American black nightshade (Solanum americanum Mill.) is highly expressed in the phloem and could be involved in regulating proteolysis in the sieve elements. To further investigate the physiological role of SaPIN2a, we have produced transgenic lettuce (Lactuca sativa L.) expressing SaPIN2a from the CaMV35S promoter by Agrobacterium-mediated transformation. Stable integration of the SaPIN2a cDNA and its inheritance in transgenic lines were confirmed by Southern blot analysis and segregation analysis of the R₁ progeny. SaPIN2a mRNA was detected in both the R₀ and R₁ transformants on northern blot analysis but the SaPIN2a protein was not detected on western blot analysis using anti-peptide antibodies against SaPIN2a. Despite an absence of significant inhibitory activity against bovine trypsin and chymotrypsin in extracts of transgenic lettuce, the endogenous trypsin-like activity in each transgenic line was almost completely inhibited, and the endogenous chymotrypsin-like activity moderately inhibited. Our finding that heterogeneously expressed SaPIN2a in transgenic lettuce inhibits plant endogenous protease activity further indicates that SaPIN2a regulates proteolysis, and could be potentially exploited for the protection of foreign protein production in transgenic plants.Abbreviations CaMV cauliflower mosaic virus - cDNA complementary DNA - NOS nopaline synthase - PAGE polyacrylamide gel electrophoresis - PI proteinase inhibitor - SaPIN2a Solanum americanum proteinase inhibitor IIa - SDS sodium dodecyl sulphate - T-DNA transferred DNA     

Purification and Characterization of a Proteinase Inhibitor from Field Bean, Dolichos lablab perpureus L.

A proteinase inhibitor resembling Bowman-Birk family inhibitors has been purified from the seeds of cultivar HA-3 of Dolichos lablab perpureus L. The protein was apparently homogeneous as judged by SDS–PAGE, PAGE, IEF, and immunodiffusion. The inhibitor had 12 mole% 1/2-cystine and a few aromatic amino acids, and lacks tryptophan. Field bean proteinase inhibitor (FBPI) exhibited a pI of 4.3 and an M _r of 18,500 Da. CD spectral studies showed random coiled secondary structure. Conformational changes were detected in the FBPI–trypsin/chymotrypsin complexes by difference spectral studies. Apparent K _a values of complexes of inhibitor with trypsin and chymotrypsin were 2.1 × 10⁷ M^?1 and 3.1 × 10⁷ M^?1, respectively. The binary and ternary complexes of FBPI with trypsin and chymotrypsin have been isolated indicating 1:1 stoichiometry with independent sites for cognate enzymes. Amino acid modification studies showed lysine and tyrosine at the reactive sites of FBPI for trypsin and chymotrypsin, respectively.     

An alkaline proteinase of an alkalophilicBacillus sp.

An alkaline serine proteinase was purfied from the culture broth of an alkalophilicBacillus sp. NKS-21. The molecular weight was estimated to be 22,000 by a gel filtration method and 31,000 by SDS-polyacrylamide gel electrophoresis. The isoelectric point was determined to be 8.2. The amino acid composition and CD spectrum were determined. The alkaline proteinase had a pH optimum at 10–11 for milk casein digestion. The specific activity of the alkaline proteinase was 0.35 katal/kg of protein at pH 10.0 for milk casein hydrolysis.The substrate specificity of the alkaline proteinase was studied by using the oxidized, insulin B-chain and angiotensin. An initial cleavage site was observed at Leu¹⁵-Tyr¹⁶, secondary site at Leu¹¹-Val¹², and additional sites at Gln⁴-His⁵, Tyr²⁶-Thr²⁷, and Asn³-Gln⁴ in the oxidized insulin B-chain at pH 10.0. In comparison with the subtilisins Carlsberg and Novo, the alkaline proteinase fromBacillus sp. showed a unique specificity toward the oxidized insulin B-chain. Hydrolysis of angiotensin at pH 10.0 with the alkaline proteinase was observed at Tyr⁴-Ile⁵. The proteinase has aK _m of 0.1 mM andk _cat of 3.3 s^–1 with angiotensin as substrate.     

Role and strain distribution of genes controlling light chains needed for the expression of an intrastrain cross-reactive idiotype

Several strains of mice were tested for their capacity to provide immunoglobulin L chains required for the expression of the major cross-reactive idiotype (CRI_A) associated with p-azophenylarsonate-specific antibodies of strain A mice. To facilitate testing, mice were bred that were homozygous for Igh-C ^e and Lyt-2 ^a , 3 ^a , i. e., they possessed genes controlling H chains but not L chains required for expression of the CRI_A. Such male mice were mated to females of various strains and their offspring were tested; expression of CRI_A indicated the presence in the female parent of genes controlling the appropriate L chains. All females bearing the Lyt-2 ^a , 3 ^b or Lyt-2 ^b , 3 ^b genotype yielded offspring, most of which were CRI _A ⁺ , whereas all the offspring of females that were Lyt-2 ^a , 3 ^a were CRI _A ^– . The female parents included mice of several strains that are congenic for Lyt-2 ^a , 3 ^b , Lyt-2 ^b , 3 ^b or Lyt-2 ^a , 3 ^b , thus demonstrating very close linkage between the Lyt loci and the expression of CRI_A. In addition, doubly congenic strains of mice with the heavy chain allotype of the CRI _A ⁺ AL/N strain and the Lyt-2 ^a , 3 ^a genotype on a BALB/c background failed to express CRI_A. The data provide further evidence for the similarity of repertoires of L chains in Lyt-3 ^b mice of various strains. When genes were present controlling A/J H chains and L chains of C57BL/6 or BALB/c origin, the quantitative expression of CRI_A was only slightly lower than that observed in A/J mice. Mice possessing genes controlling the H or L chains required for CRI_A expression, but not both, did not express CRI_A but synthesized Ar-specific antibodies which contained low but significant concentrations of the idiotype-associated chain.     

Binding of the Recombinant Proteinase Inhibitor Eglin c,of the Soybean Bowman-Birk Proteinase Inhibitor and of its Chymotrypsin and Trypsin Inhibiting Fragments to Leu-Proteinase,the Leucine Specific Serine Proteinase from Spinach (Spinacia oleracea L.) Leaves: Thermodynamic Study

Abstract

The effect of pH and temperature on the apparent association equilibrium constant (K_a) for the binding of the recombinant proteinase inhibitor eglin c (eglin c), of the soybean Bowman-Birk proteinase inhibitor (BBI) and of its chymotrypsin and trypsin inhibiting fragments (F-C and F-T, respetively) to Leuproteinase, the leucine specific serine proteinase from spinach (Spinacia oleracea L.) leaves, has been investigated. On lowering the pH from 9.5 to 4.5, values of K_a (at 21°C) for complex formation decrease thus reflecting the acidic pK-shift of the hystidyl catalytic residue from ～6.9, in the free Leu-proteinase, to ～5.1, in the enzyme: inhibitor adducts. At pH 8.0, values of the apparent thermodynamic parameters for the proteinase:inhibitor complex formation are: Leu-proteinase:eglin c - K_a = 2.2 × 10¹¹ M^-1, δG°= - 64kJ/mol, δH° = + 5.9kJ/mol, and δS° = + 240J/molK; Leu-proteinase:BBI - K_a = 3.2 × 10¹⁰ M^-1, δG° = - 59kJ/mol, δH°= + 8.8kJ/mol, and δS° = + 230J/molK; and Leu-proteinase:F-C - K_a = 1.1 × 10⁶ M^-1, δG°= - 34kJ/mol, δH° = + 18J/mol, and δS° = + 180J/molK (values of K_a, δG° and δS° were obtained at 21.0°C; values of δH° were temperature-independent over the range explored, i.e. between 10.0°C and 40.0°C). F-T does not inhibit Leu-proteinase up to an inhibitor concentration of 1.0 × 10^-3 M, suggesting that the upper limit of K_a is 1 × 10² M^-1. Considering the known molecular models, the observed binding behaviour of eglin c, BBI, F-C and F-T to Leu-proteinase has been related to the inferred stereochemistry of the enzyme/inhibitor contact region     

Molecular analysis of glycinin genes in soybean mutants for development of gene-specific markers

Soybean mutant lines that differ in 11S glycinin and 7S β-conglycinin seed storage protein subunit compositions were developed. These proteins have significant influence on tofu quality. The molecular mechanisms underlying the mutant lines are unknown. In this study, gene-specific markers for five of the glycinin genes (Gy1 to Gy5) were developed using three 11S null lines, two A₄ null Japanese cultivars, Enrei and Raiden, and a control cultivar, Harovinton. Whereas gene-specific primers produced the appropriate products in the control cultivar for the Gy1, Gy2, Gy3 and Gy5 genes, they did not amplify in mutants missing the A_1aB₂, A₂B_1a, A_1b B_1b, and A₃B₄ subunits. However, ecotype targeting induced local lesions in genomes (EcoTILLING) and sequencing analysis revealed that the absence of the A₄ peptide in the mutants is due to the same point mutation as that in Enrei and Raiden. Selection efficiency of the gene-specific primer pairs was tested using a number of breeding lines segregating for the different subunits. Primer pairs specific to each of the Gy1, Gy2, Gy3, and Gy5 genes can be used to detect the presence or absence of amplification in normal or mutant lines. The Gy4 null allele can be selected for by temperature-switch PCR (TS-PCR) for identification of the A₄ (G4) null genotypes. In comparison to protein analysis by SDS-PAGE, gene-specific markers are easier, faster and more accurate for analysis, they do not have to use seed, and can be analyzed at any plant growth stage for marker-assisted selection.     

Inhibition Mechanism and the Effects of Structure on Activity of Male Reproduction-Related Peptidase Inhibitor Kazal-Type (MRPINK) of Macrobrachium rosenbergii

In our previous reports, a Kazal family serine protease inhibitor, male reproduction-related peptidase inhibitor Kazal-type (MRPINK) has been identified from the prawn, Macrobrachium rosenbergii, and discovered having an inhibitory effect on the sperm gelatinolytic activity. MRPINK was predicated to inhibit chymotrypsin since it contains leucine and proline at P₁ positions of the two domains, respectively. In this report, recombinant MRPINK was as expected found to specifically inhibit chymotrypsin, but no inhibition was detected against trypsin or thrombin. By the analysis of kinetic tests, the inhibition mechanism of MRPINK was determined to be typical competitive model with K _i of 354 nM. To elucidate the effects of structure on activity of MRPINK, the mutants (domain-1 only, domain-2 only, MRPINK^P88I, MRPINK^L37K, MRPINK^L37A, and MRPINK^L37G) were prepared and their inhibitory activities assayed. The results showed that domain-2 was the key contributor to the inhibition of chymotrypsin (K _i of 416 nM) and P₁ Pro was crucial for the activity. Nevertheless, whether the P₁ amino acid residue was Leu, or even if it was replaced by Lys, Ala, or Gly, domain-1 was ineffective to the activity.     

Prt-4 and Prt-5: New constituents of a gene cluster on chromosome 7 coding for esterproteases in the submandibular gland of the house mouse (Mus musculus)

The heredity and linkage of gene loci were established for two different enzymes with esterproteolytic activity from mouse submandibular gland: protease A and protease E. Based upon strain distribution and biochemical properties of the two esterproteases, the existence of two corresponding structural loci is proposed: Prt-4 (protease A) and Prt-5 (protease E). Prt-4 and Prt-5 proved to be different from Tam-1. From a four-point-cross, the gene order Gpi-1-(Tam-1, Prt-4, Prt-5)-c is suggested. Thus a gene cluster was shown to exist on chromosome 7 coding for esterproteases, all of which are controlled by testosterone.This work was supported by grants from the Deutsche Forschungsgemeinschaft, Bonn (SFB 46).     

Calcium protects DNase I from proteinase K: a new method for the removal of contaminating RNase from DNase I

DNase I and proteinase K are two enzymes commonly used in the purification of highly polymerized RNA. In the presence of EDTA DNase I is rapidly inactivated by proteinase K while in 10 mm Ca²⁺ DNase is totally immune to proteinase K inactivation even at protease concentrations of up to 1 mg/ml. RNase A, a common contaminant of “RNase-free” DNase was inactivated by proteinase K in the presence or absence of Ca²⁺. Treatment of DNase I with proteinase K in the presence of Ca²⁺ selectively removed RNase A activity as judged by rRNA and poly(A⁺ RNA ribosomal RNA degradation monitored by sucrose gradient centrifugation. These results suggest that (i) DNase A and proteinase K can be used together in the presence of Ca²⁺ to obtain better digestion of nucleoprotein complexes, and (ii) proteinase K treatment of Ca²⁺ DNase can be used to selectively remove contaminating RNase.