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At least 19 recordsLinked to original sources
PubMed1989

Association of protamine IgE and IgG antibodies with life-threatening reactions to intravenous protamine.

Life-threatening reactions to intravenous protamine, administered to reverse heparin anticoagulation, have been reported with increasing frequency as a consequence of the escalating use of cardiac catheterization and coronary bypass surgery. Retrospective studies have shown that such reactions are more common in diabetic patients receiving daily subcutaneous injections of protamine-insulin preparations. To determine whether anti-protamine IgE or IgG antibodies might explain the increased risk for protamine reactions among patients with protamine-insulin-dependent diabetes, we conducted a case-control study of 27 patients (diabetic and nondiabetic) who had acute reactions to intravenous protamine and 43 diabetic patients who tolerated protamine without a reaction during diagnostic or surgical procedures. Cases and controls were grouped according to previous exposure to protamine-insulin preparations. In diabetic patients who had received protamine-insulin injections, the presence of serum antiprotamine IgE antibody was a significant risk factor for acute protamine reactions (relative risk, 95; P = 1.0 X 10(-5), as was antiprotamine IgG (relative risk, 38; P = 1.2 X 10(-5). No patients without previous exposure to protamine-insulin injections had serum protamine IgE antibodies. In this group, anti-protamine IgG antibody was a risk factor for protamine reactions (relative risk, 25; P = 0.0062). We conclude that in protamine-insulin-dependent diabetics, the increased risk of serious reactions when intravenous protamine was given appeared to be caused largely by antibody-mediated mechanisms. In nondiabetic subjects, the presence of protamine IgG was significantly associated with an increased risk of acute protamine reactions, although many nondiabetic subjects who had reactions had no IgG antibodies.

Adult↗
PubMed2001

Repeated administration of protamine does not attenuate circulatory changes caused by protamine reversal of heparin in dogs.

OBJECTIVE: To determine whether repeated administration of protamine attenuates circulatory changes caused by protamine reversal of heparin and to evaluate the significance of nitric oxide generation. DESIGN: Prospective, randomized, controlled, animal study. SETTING: University research laboratory. PARTICIPANTS: Twenty-seven adult mongrel dogs. INTERVENTIONS: The animals were randomly assigned to 3 groups (n = 9 in each) according to the pretreatment. The control group was pretreated with normal saline, and the 2 other groups were given 2 different doses of protamine: protamine 0.1 (protamine, 0.1 mg/kg) and protamine 1.0 (protamine, 1.0 mg/kg). Under general anesthesia, all animals were anticoagulated with intravenous heparin, 200 IU/kg. Five minutes after heparin injection, preadministered saline (control) or protamine in saline was infused during 60 seconds. Five minutes after the pretreatment, protamine, 2.0 mg/kg in control, 1.9 mg/kg in protamine 0.1, or 1.0 mg/kg in protamine 1.0, was administered intravenously during 10 seconds. MEASUREMENTS AND MAIN RESULTS: Percent changes in mean arterial blood pressure among the 3 groups at each period were not significantly different except 60 minutes after protamine infusion. Mean pulmonary arterial pressure in the protamine 1.0 group at 5, 15, 20, and 60 minutes was higher than in the control group. Serum nitrate concentration was not significantly different among the 3 groups at baseline and 10 minutes after protamine injection. CONCLUSION: Repeated administration of protamine does not attenuate circulatory changes caused by protamine reversal of heparin in dogs. Nitric oxide generation does not appear to be responsible for the phenomenon.

Animals↗
PubMed1996

Single doses of intravenous protamine result in the formation of protamine-specific IgE and IgG antibodies.

BACKGROUND: Protamine reactions are a well-recognized and serious complication of intravenous protamine administration. IgE-mediated anaphylaxis occurs after initial sensitization and subsequent re-exposure to antigens. Subcutaneous protamine in insulin preparations is associated with protamine-specific IgE and IgG antibody production. In contrast, the influence of intravenous protamine administration on protamine-specific IgE and IgG antibody formation has never been investigated. METHODS: Sera from 93 patients were analyzed for protamine-specific IgE and IgG antibodies both before and 4 to 6 weeks after exposure to single doses of intravenous protamine. Specific clinical variables were assessed by univariate and multivariate analyses to determine independent predictors of protamine-specific antibody production. RESULTS: In patients who were previously seronegative, intravenous protamine administration resulted in protamine-specific IgE and IgG antibody production in 17 of 93 (18%) and 15 of 93 (16%) patients, respectively. As determined by multivariate analysis, male gender (p = 0.06) and insulin-dependent diabetes mellitus (p = 0.002) were associated with protamine-specific IgG but not IgE antibody production. CONCLUSION: Single-dose intravenous protamine resulted in protamine-specific IgE and/or IgG antibody production in 26 of 93 (28%) of patients. Seroconversion was associated with male gender and insulin-dependent diabetes mellitus. Patients responding immunologically to protamine may be at increased risk for experiencing reactions on subsequent exposure.

Aged↗
PubMed1991

The use of immobilized protamine in removing heparin and preventing protamine-induced complications during extracorporeal blood circulation.

Heparin, currently used in extracorporeal blood circulation procedures, may lead to hemorrhagic complications. Protamine, used for reversal of heparin-induced anticoagulation at the end of such procedures, can cause adverse hemodynamic responses. To prevent both types of complications, we have developed a reactor device containing immobilized protamine (i.e., a protamine bio-reactor) that can be placed at the distal end of the circuit, thus providing simultaneous extracorporeal heparin removal and protamine treatment. In preliminary in vivo studies involving dogs at a blood flow of 100 ml/min, the bio-reactor removed about 50% of the administered dose of heparin (i.e., 100 units/kg) in 10 min. While rapid injection of protamine in dogs anticoagulated with heparin produced a transient and significant (P less than 0.005) decreases in systemic arterial blood pressure (-39.5 +/- 9.2 mmHg), cardiac output (-1.59 +/- 0.23 L/min), and mixed venous oxygen saturation (-7.5 +/- 1.3%) and increases in pulmonary artery systolic (+12.7 +/- 4.4 mmHg) and diastolic pressures (+10.0 +/- 3.6 mmHg), the use of the protamine bio-reactor did not elicit any statistically significant change in any of the variables measured. Hemolysis was not significant, as reflected by a statistically insignificant change of the animals' red blood cell counts, hematocrits, and total hemoglobin values. In addition, hemolytic complement was found to be reduced only by 10% in animals with the protamine bio-reactor, whereas it was reduced rapidly by 20% in animals receiving intravenous protamine administration and progressively by 20% in control animals with a sham reactor that contained no protamine. Furthermore, the use of the protamine bio-reactor also significantly reduced the protamine-induced transient thrombocytopenic and granulocytopenic responses. The white blood cell counts and platelet counts decreased to 87.7 +/- 7.5 and 83.3 +/- 5.0% of baseline, respectively, in dogs with the protamine bio-reactor compared to 35.5 +/- 14.3 and 32.1 +/- 8.1% of baseline in dogs receiving intravenous protamine. The protamine bio-reactor may provide a unique means to simultaneously control both heparin- and protamine-induced complications.

Animals↗
PubMed1994

P2 protamines are phosphorylated in vitro by protein kinase C, whereas P1 protamines prefer cAMP-dependent protein kinase. A comparative study of five mammalian species.

P1 protamines isolated from ejaculated human, stallion, bull, boar and ram spermatozoa and P2 protamines from human and stallion spermatozoa were subjected, after alkaline phosphatase treatment, to in vitro phosphorylation reactions using cAMP-dependent protein kinase (PKA) and protein kinase C (PKC). All P1 protamines were phosphorylated by PKA, whereas P2 protamines were phosphorylated only by PKC. In addition, human, stallion and boar, but not bull and ram, P1 protamines were phosphorylated by PKC. After phosphoamino acid analysis, the protamines showing positive signals for phosphoserine (P-Ser) were subjected to P-Ser conversion reaction and protein sequencing. Only stallion (St1) and human (HP1) P1 protamines contained P-Ser after PKA phosphorylation, located in the middle region of the molecule, i.e., at Ser29 in St1 and Ser28 in HP1. All other phosphorylated P1 protamines contained only P-Thr, which could not be further localized in the sequence with the present methods. After PKC phosphorylation, the internally located Ser residues in human (ser21) and stallion (Ser29) P1 protamines were phosphorylated and, in boar P1 protamine, only Thr43 was slightly phosphorylated. The N-terminally located Ser residues in P1 protamines, which are known to be phosphorylated in vivo, were not phosphorylated by either kinase, indicating that there must still be other types of protamine kinases in sperm cells responsible for their phosphorylation. Within P2 protamines, HP2 was equally well phosphorylated at all Ser residues in addition to some Thr phosphorylation, whereas, in St2, Ser32 was the main target for PKC phosphorylation in vitro. Collectively, PKC is a good candidate for in vivo phosphorylation of P2 protamines and PKA for phosphorylation of some hydroxyamino acid residues in P1 protamines.

Amino Acid Sequence↗
PubMed1996

Stimulation of phosphorylase phosphatase activity of protein phosphatase 2A1 by protamine is ionic strength dependent and involves interaction of protamine with both substrate and enzyme.

The effects of protamine on the phosphorylase phosphatase activity of porcine cardiac protein phosphatase 2A1 (PP2A1) were complex and ionic strength dependent. Under ionic strength conditions that protamine activation was optimal, activation of PP2A1 by either dilution or heparin was prevented. A time-dependent deactivation of the protamine-stimulated phosphatase activity was observed when PP2A1 was preincubated with protamine. Protamine forms a very tight association with phosphorylase a, which is optimal at a 1:1 protamine:phosphorylase a monomer molar ratio. Protamine activation of PP2A1 activity, however, is not substrate-directed since the basic polypeptide did not stimulate either the activity of the catalytic subunit or trypsinolysis of [32P]phosphorylase a. The interaction of protamine with phosphorylase a does not apparently involve the phosphorylation site in the protein substrate (ser 14). The activation of PP2A1 by protamine is proposed to involve part of the basic polypeptide, not associated with phosphorylase a monomer, interacting with the regulatory and/or the catalytic subunit(s) of the phosphatase. A minimal model for the activation of PP2A1 by protamine was tested kinetically. In this model, free PP2A1 binds with decreasing affinities to the protamine:phosphorylase a complex, free phosphorylase a, and free protamine. Protamine decreases the K(m) of PP2A1 for the phosphorylase a monomer 5-fold and increases the Vmax 17-fold. Interaction of free protamine with PP2A1 inhibits the phosphatase activity.

Animals↗
PubMed1996

[Repeated administration of protamine attenuates protamine-induced systemic hypotension].

Protamine may act on endothelial cell receptors to stimulate the production of nitric oxide, which would promote vasodilation. If so, the repeated administration of protamine may attenuate protamine-induced systemic hypotension. To confirm this hypothesis, we examined whether repeated administration of protamine attenuates protamine-induced systemic hypotension in rats. Rats were divided into two groups. In bolus injection group (S group), protamine was given intravenously at 10 mg.kg-1. In repeated administered group (R group), the same dose of protamine was given intravenously 30 min after continuous infusion of protamine 10 mg.kg-1. The mean arterial pressure in S group decreased significantly after administration of protamine, compared with R group. Also, maximal decrease rate of the arterial pressure after administration of protamine in R group was significantly lower than in S group. These results demonstrate that repeated administration of protamine attenuates protamine-induced systemic hypotension. We confirm the hypothesis that protamine will release nitric oxide by binding with the receptor on the endothelium in the vessel and subsequently cause systemic hypotension.

Animals↗
PubMed1993

Imaging the ovine heparin-protamine interaction with 111In-protamine.

Protamine reversal of heparin anticoagulation occasionally induces the release of thromboxane into plasma with catastrophic pulmonary hypertension. To examine the site of neutralization, we labeled protamine sulfate with 111In and compared activity scans after administration of labeled protamine in unheparinized and heparin-anticoagulated sheep. Protamine administration in sheep without prior heparinization did not cause thromboxane release, pulmonary hypertension, or significant leukopenia, and 111In-protamine was rapidly cleared from the lungs (half time 0.48 +/- 0.08 min). Neutralization of heparin anticoagulation by labeled protamine produced elevated plasma thromboxane, pulmonary vasoconstriction, leukopenia, and prolonged pulmonary clearance of 111In-protamine (half time 3.32 +/- 0.43 min). In rats, protamine reversal of heparin anticoagulation did not induce either thromboxane synthesis or pulmonary hypertension, and 111In-protamine cleared rapidly from the lungs. Thus the ovine heparin-protamine reaction produces concomitant pulmonary sequestration of heparin-protamine complexes, thromboxane release, and pulmonary vasoconstriction; this did not occur in the rat. The lung specificity of the reaction and interspecies differences suggest that ovine pulmonary intravascular macrophages may be activated by heparin-protamine complexes to release thromboxane and provoke acute pulmonary vasoconstriction.

Animals↗
PubMed1999

Low-dose protamine based on heparin-protamine titration method reduces platelet dysfunction after cardiopulmonary bypass.

OBJECTIVE: The heparin-protamine titration method that uses the Hepcon hemostasis management system (Medtronic HemoTec Inc, Englewood, Colo) reduced blood loss in cardiac surgery in previous reports, but the mechanism is not fully understood. This study tests the hypothesis that reduced protamine administration preserves platelet function in human cardiac surgery. METHODS: Platelet count, alpha-granule secretion, and aggregation to thrombin before and after cardiopulmonary bypass in human beings were evaluated. In the control group (n = 14), a fixed dose of protamine (3 mg/kg) was administered. In the titration group (n = 20), protamine doses were based on the heparin concentration measured by the Hepcon system. RESULTS: Heparin concentrations before protamine administration were higher in the titration group (P =.0012), but protamine doses of patients in the titration group were markedly lower than those of the control group (P <.0001). During protamine infusion at a rate of 0.3 mg. kg(-1). min(-1), the percentage of granule membrane protein-140-positive platelets significantly increased in the control group compared with the titration group (18.8% +/- 8.6% vs 13.0% +/- 5.3%, P =.0188). After protamine administration, aggregation of washed platelets to thrombin recovered almost to the preoperative level in the titration group; however, it remained lower in the control group (20% +/- 20% vs 55% +/- 18%, P =.0009). CONCLUSION: Low-dose administration of protamine, based on a heparin-protamine titration method, restores not only the blood coagulation but also the platelet responses to thrombin and attenuates platelet alpha-granule secretion during heparin neutralization. Overdose of protamine activates platelets and may predispose patients to excessive bleeding after cardiac surgery.

Blood Loss, Surgical↗
PubMed1992

Protamine induces autophosphorylation of protein kinase C: stimulation of protein kinase C-mediated protamine phosphorylation by histone.

Protein kinase C (PKC), a protein phosphorylating enzyme, is characterized by its need for an acidic phospholipid and for activators such as Ca2+ and diacylglycerol. The substrate commonly used in experiments with PKC is a basic protein, histone III-S, which needs the activators mentioned. However, protamine, a natural basic substrate for PKC, does not require the presence of cofactor/activator. We report here that protamine can induce the autophosphorylation of PKC in the absence of any PKC-cofactor or activator; this may represent a possible mechanism of cofactor-independent phosphorylation of this protein. It was investigated if protamine itself can act as a PKC-activator and stimulate histone phosphorylation in the manner of Ca2+ and phospholipids. Experiments however showed that protamine is not a general effector of PKC. On the contrary, histone stimulated PKC-mediated protamine phosphorylation and protamine-induced PKC-autophosphorylation. Histone alone did not induce PKC-autophosphorylation. Kinetic studies suggest that histone increases the maximal velocity (Vmax) of protamine kinase activity of PKC without affecting the affinity (Km). Other polycationic proteins such as polyarginine serine and polyarginine tyrosine were not found to influence PKC-mediated protamine phosphorylation, indicating that the observed effects are specific to histone, and are not general for all polycationic proteins. These results suggest that histone can modulate the protamine kinase activity of PKC by stimulating protamine-induced PKC-autophosphorylation.

Animals↗
PubMed1991

Heparin rebound: a comparative study of protamine chloride and protamine sulfate in patients undergoing coronary artery bypass surgery.

Heparin rebound has been suggested to occur when protamine sulfate, but not protamine chloride, is used to neutralize heparin. This study was undertaken to compare these two protamine salts in 32 patients undergoing coronary artery bypass surgery. Initial heparin and subsequent protamine doses were determined by constructing a heparin-activated coagulation time response curve. Heparin was neutralized either with protamine sulfate or protamine chloride. The total protamine/heparin dose ratio was 0.71 +/- 0.05 for protamine sulfate and 0.77 +/- 0.07 (mg/100 U) for protamine chloride. The initial neutralization effect, the subsequent behavior of the plasma heparin level, and the various coagulation parameters did not differ significantly between the groups. Two hours after neutralization, a small and temporary increase of plasma heparin level was observed in both groups. The postoperative blood losses were comparable in both groups. Thus, protamine chloride was not a clinically superior antidote to heparin than protamine sulfate. The observed heparin rebound levels were low and clinically insignificant in terms of blood loss, but they were associated with slight changes in coagulation monitoring.

Blood Coagulation↗
PubMed1991

Protamine allergy reactions during cardiac catheterization and cardiac surgery: risk in patients taking protamine-insulin preparations.

Protamine insulin use may immunologically sensitize patients to protamine, leading to anaphylactoid reactions upon subsequent exposure to protamine sulfate during cardiac catheterization or cardiovascular surgery. The risk of such reactions in protamine insulin-dependent patients is uncertain. One catheterization study reported a 50-fold greater risk while a second showed no increased risk! To clarify the risk, the records of 7,750 cardiac catheterization procedures between 1984 and 1987 were analyzed for presence of NPH or PZI insulin use, protamine administration, and any complications or adverse reactions. Protamine was administered in 3,341/7,750 procedures (43%), including 171 in diabetics receiving NPH insulin. Adverse reactions to protamine occurred in 2/3, 170 noninsulin patients, 0.06%, and adverse reactions due to probable NPH insulin sensitization occurred in 1/171, 0.6%, of NPH diabetics, p = .034. Meta-analysis of risk showed an odds ratio of 7.96 for the NPH diabetic patients, and combining these results with the other large series in the literature (269 NPH diabetics total) showed an odds ratio of 4.19 compared to a non-NPH insulin group. Meta-analysis of the surgical literature showed the risk in surgical patients to be 2.1% in NPH patients versus 0.12% with no NPH, with an odds ratio of 15.52. The greater incidence in surgical patients may be due to protamine sensitization at prior catheterization and to the larger dose of protamine administered to surgical patients.

Anaphylaxis↗
PubMed1987

Translation of mouse testis poly(A)+ mRNAs for testis-specific protein, protamine 1, and the precursor for protamine 2.

Since previous studies have suggested that the mammalian protamine mRNAs are translated poorly in cell-free systems, we directly measured the efficiency of translation of mouse protamine 1 mRNA. We found that mouse testis poly(A)+ mRNA stimulates the synthesis in the wheat germ and reticulocyte cell-free systems of three prominant translation products which can be resolved by electrophoresis through acid urea polyacrylamide gels containing 8 M urea. These translation products have been identified as testis-specific protein, protamine 1, and the precursor to protamine 2 by several criteria, including labeling with amino acids, [35S]cysteine, and [3H]leucine, which are known to be specific to some of these proteins from the nucleotide sequences of recombinant DNAs. Surprisingly, the mobility of the testis-specific protein translation product is slightly reduced and the mobility of both protamine translation products is drastically reduced unless the extracts of cell-free translations are coelectrophoresed with the appropriate carrier. The fraction of [35S]cysteine- labeled protamine 1 translation product was compared with the fraction of testis poly(A)+ mRNA as protamine 1 mRNA which we measured in dot blots with the use of an SP6 RNA polymerase transcript for protamine 1. The results demonstrate that protamine 1 mRNA is translated only slightly less efficiently than the average testis poly(A)+ mRNA.

Animals↗
PubMed2003

Effect of site of venous protamine administration, previously alleged risk factors, and preoperative use of aspirin on acute protamine-induced pulmonary vasoconstriction.

OBJECTIVE: To determine whether the incidence of protamine-induced pulmonary vasoconstriction (PIPV) is influenced by central venous versus peripheral venous infusion of protamine and whether aspirin ingestion within a week of surgery would decrease the incidence of PIPV. DESIGN: Single-institution, prospective, observational, randomized trial. SETTING: University teaching hospital. PARTICIPANTS: One thousand four hundred ninety-seven consecutive patients undergoing cardiopulmonary bypass procedures. INTERVENTION: Protamine neutralization of heparin by infusion pump via either central venous or peripheral venous route. MEASUREMENTS AND MAIN RESULTS: Five previously suspected risk factors (valve surgery, prior protamine exposure, history of pulmonary hypertension, fish allergy, and vasectomy), aspirin ingestion within 7 days of surgery, and demographic information were recorded. PIPV was defined as an abrupt increase in mean PA pressure of 7 mmHg or more with associated right ventricular dysfunction as assessed by observation of the right ventricle in the field and regional wall motion abnormality by transesophageal echocardiogram and hypotension (systolic blood pressure < or = 90 mmHg). Data were collected via continuous strip chart recording. A total of 10 patients (0.6%) developed PIPV during protamine infusion. The incidents were similar with respect to the site of venous administration. Prior exposure to protamine was associated with a greater incidence of PIPV (odds ratio 6.9; p < 0.01). Other previously suspected risk factors did not achieve statistical significance. None of the 766 patients who ingested aspirin experienced PIPV as opposed to 10 of the 731 patients who did not ingest aspirin (odds ratio 0.08; p < 0.001). CONCLUSIONS: Although the site of venous protamine administration does not influence incidence of PIPV, aspirin ingestion within 1 week of surgery may decrease it. These data also confirmed other studies suggesting that previous protamine administration predisposes to this protamine reaction.

Acute Disease↗
PubMed1987

Cloning of bovine P1 protamine cDNA and the evolution of vertebrate P1 protamines.

A bovine P1 protamine cDNA from a bull testis cDNA library was isolated utilizing a series of oligonucleotide probes. Sequence analysis showed that the cloned cDNA insert extended 317 bp to the poly(A) tail. The 51-residue 6750-dalton protamine primary translated protein is encoded within a 156-bp segment. The protamine sequence predicted from the cDNA sequence differs from that previously reported for the amino acid sequence of bovine protamine P1 by the insertion of the tripeptide Cys-Arg-Arg from residues 39-41 in the carboxy-terminal region of the mature protein. Consistent with previous hybridization analysis, nucleotide sequence comparisons showed that trout protamine cDNA was more closely related to that of bovine than to that of mouse. However, bovine P1 protamine cDNA shared greater sequence homology with mouse P1. A common nucleotide sequence of 30 bp is conserved among all three of these species. Primer extension analysis revealed that, as with trout protamine mRNAs, the majority of the untranslated portion of the mRNA lies 3' to the coding segment. Comparisons of their mRNA secondary structures by computer modeling indicate that the mRNAs fold back onto themselves, producing similar, extensively hydrogen-bonded, convoluted forms. These models support the view that translational regulation of protamine mRNA may be partially dependent on secondary structure. Southern analysis suggests that the bovine protamine P1 gene is not sex-linked and is present as one (or relatively few) copy within the bovine genome.

Amino Acid Sequence↗
PubMed1989

Quail (Coturnix japonica) protamine, full-length cDNA sequence, and the function and evolution of vertebrate protamines.

Using the chicken protamine gene as a probe, we have isolated and sequenced several positive clones from a quail testis cDNA library which reveal the complete sequence for the quail protamine cDNA. The predicted amino acid sequence for the quail protamine contains the N-terminal tetrapeptide ARYR present in the N-terminal region of the mammalian protamines as well as several conserved motifs and arginine clusters. In addition the size of the quail protamine (56 amino acids) is closer to that of mammals (50 amino acids) than that of the chicken (61 amino acids). Altogether this data strongly suggests the existence of an avian-mammalian protamine gene line during evolution. Southern blot analysis suggests a small number of copies (2) per haploid genome (similar to that of chicken). The reported quail protamine cDNA sequence is the second avian protamine for which the amino acid sequence is available so far and provides new insights into vertebrate protamine function and evolution.

Amino Acid Sequence↗
PubMed1977

Sequence analysis of protamine mRNA from the rainbow trout. Depurination and nearest neighbor analysis of protamine cDNA.

Protamine cDNA, which was a full length copy of protamine mRNA was labeled during its synthesis by using deoxynucleoside [alpha-32P]triphosphates. Depurination analysis showed that there were 19 different pyrimidine oligonucleotides in protamine cDNA, some of which contained isomeric sequences. The stoichiometry of the pyrimidine oligonucleotides indicated that, while some sequences probably occur in each of the protamine mRNA components, other sequences are clearly absent from one or more of the components. Several of the pyrimidine oligonucleotides had sequences consistent with the amino acid sequences of the rainbow trout protamines. The longest oligopyrimidine tract, C7T4, had a complementary RNA sequence of AGGAGAGGAGG, a stoichiometry of close to 1, and fitted the amino acid sequence Arg-Arg-Gly-Gly which occurs near the COOH terminus of each of three major protamine components. Other pyrimidine oligonucleotides analyzed were complementary to RNA sequences from the noncoding region of protamine mRNA. There appears to be no preferential use of one particular arginine codon or set of codons. Of the 21 to 22 arginine codons in protamine mRNA no less than 7 and no more than 12 are of the CGX series. The other two codons, AGA and AGG, both occur but not in a series of more than two together. This indicates that the RNA sequences coding for the arginine tracts tend to contain a mixture of arginine codons. Nearest neighbor frequency analysis of protamine cDNA gives a low value for the frequency of the CpG doublet, despite its occurrence in four out of the six arginine codons. This is in accordance with the observation that the sequence CpG is surprisingly rare in vertebrate DNA and in the RNA transcribed from it.

Animals↗
PubMed1983

Circulating IgG antibody to protamine in patients treated with protamine-insulins.

Sera from patients with different types of protamine-insulin were assayed for IgG antibody to protamine. A high prevalence of circulating antibody was found in patients treated with either bovine isophane insulin (26 out of 28 patients; 26 of whom also had antibodies to insulin), or bovine protamine zinc insulin (27 out of 30 patients; all 30 had antibodies to insulin). In sera from 24 patients treated with highly purified porcine isophane insulin, protamine antibody was detected in nine; circulating insulin-antibody was detected in 12 patients, eight of whom had protamine-antibody; in the 12 patients with no detectable antibody to insulin, antibody to protamine was detected in only one (x2 = 8.7, p less than 0.01). This relationship between insulin and protamine antigenicity is of interest as it suggests that the protamine-insulin complex is itself immunogenic.

Adolescent↗